AC Owners Club Forum
AC Owners Club Forum => Ace, Aceca & Greyhound Forum => Topic started by: AEX 31 on June 23, 2022, 15:06:01
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Dear all,
AEX 31 has done something like 80.000 km and so has the steering box. With the help of a knowledgeable friend we replaced all the moving parts that we could so I guess it’s as good as it can get, without changing the worm and peg, so with modern Michelin X’s it’s tracking a bit at higher speeds.
So my question is simple, is there anybody out there that has a very good or even nos steering box or at least a new worm and maybe a column that they want to sell? To me!
I know one can buy new worms from TR specialists but I have also heard that the quality of these new worms aren’t very good. Also if anybody has any experience with new parts and tracking problems in general it would be interesting to hear about the experience that others with old Ace’s and Aceca’s have had.
Many thanks in advance for any input.
Kind regards
Jonas
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Jonas,
The Ace is not prone to tracking or tramlining, neither are Michelin X tyres.
I wonder if you have lost the caster self centering action by over tightening the adjustment on the peg ? There should be some play at the steering wheel rim.
The cam doesn't wear like the peg and I would fit just a new peg and adjust the clearance to allow the wheel to self centre as soon as you relax your grip on the steering wheel whilst turning.
Fitting the front uprights on the wrong side gives you reverse caster angle and some epic directional excursions - I hope '31 has not suffered this insult.
Barrie
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There used to be a gentleman in Westcott ,Surrey who specialised in worm and peg boxes and about 10 years ago he overhauled mine.
I had a quick look on the internet but cannot find him........maybe a more in depth look may uncover his whereabouts........or maybe somebody else on the forum can shed some light on the matter.......
Sorry to be a bit vague.....Luke
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MarlesWellerBox David Cornwallis is probably the guy they are on the web!
Robin
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Many thanks for your input.
Barrie, I do think the uprights are fitted the correct way. Both sides have a positive caster of between 3 and 4 degrees. So hopefully no insult to the old lady (31!).
I will definitely try to let the peg sit with less force and see if that changes matters. I have also enclosed an image of the worm. Maybe hard to see but there is some wear, especially in the center of the worm. I do think my worm Is just worn, maybe from historical over tightening?
Regardless I do think that the modern Michelin X’s are rather different to the older ones. First of all the later versions have an almost 20 mm larger diameter, different thread pattern and probably a different rubber specification. I definitely feel a large difference to the older ones when cornering, the new type sticks to the road much, much better.
Robin, I have had some contact with the Marles company. I can see on their website that they have restored a number of the Bishops boxes for AC’s. Do you or anybody else on the forum have any first hand experience with them and the quality of their work?
A last thought I have is that toe in should play a large part as well. 31 is set up with roughly 0,25 degrees per side, which should equate to the 1/16 inch as it says in the handbook. Anybody with different opinion/experience concerning toe in? I run the car with the original 16 inch wheels.
Thanks again.
Jonas
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Jonas,
Do bear in mind that the cam is machined to give more clearance to the peg in the straight head area. This is the reason why the peg must not be set too close - it will bind as lock is applied
Barrie
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We used parts and advice from Marles to successfully rebuild the steering box in an Allard K3. The company was quite helpful. I sold the car a few years ago and all the paperwork went with it, so I can't provide any more details.
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Gentlemen,
Thanks for your reply’s. Barrie, are you a 100 % sure that the cam is machined to give more clearance in the centre of the cam? There is one thing that I find intriguing and that
is that the peg is past the centre of the cam in the straight ahead area, which would mean that the peg, theoretically, wouldn't have any contact at all with the sides of the cam,
unless the cam is machined with different angles.
To make things even more complicated for my little brain a friend of mine sent me this text:
https://ttypes.org/keeping-it-on-the-straight-and-narrow-aspects-that-affect-tatbtc-steering-part-7/
The text is about steering boxes for MG TA-TC, but still a Bishops box that I presume would be designed, and machined in a similar fashion?
If that is correct this text assumes that the peg clinches, or meshes with the cam in the dead center position and towards the stop of the travel.
Greatful for any comments.
Kind regards
Jonas
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Jonas,
Just for background, my Ace has never had tracking problems on Michelin, Cinturato or Avon Turbospeeds. It has the original unrestored box and has done about 450,000 km. The only problems are a leak at the oil seal and it's too heavy for my partner.
I assume all ball joints are sound.
Regards
Ron
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Ron,
Thanks for your input. I have to say that 450.000 km is rather impressive, have you done many of these miles yourself?
I’m also curious as to what tires you are running with at present.
The funny thing for me is that I never used to have any tracking problems before 31 was restored, sometimes I wonder if it’s also an older version of myself, that’s more used to modern cars that’s the biggest problem. I have had 31 for 22-23 years now…
Anyway. All the ball joints were changed when the car was restored, which is now only some 6-7000 km ago.
After having rechecked everything I found that the front steering idler was a bit stiff and after sorting this my car isn’t tracking as much. However I am still wondering if possibly I should set it up with a bit more toe in, at the moment the total toe in is 0,5 degrees.
So still interested to hear what toe in other members have on their cars, that have 16 inch wheels.
Thanks in advance for any input.
Jonas
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Hi Jonas,
I have done about 315,000 Km over 52 years.
I am using 165x16 Avon Turbosteels, which are good enough.
My official AC handbook says that if you adjust the steering box correctly, it will give unlimited service!
I run mine with i/16 inch toe in on each wheel at the wheel rim. This is as recommended in the handbook.
I agree that old cars and poor roads need a certain technique.
If the idler was stiff could there be wear in the mounting bolt fixing holes, allowing up and down movement?
Cheers
Ron
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Hi Ron,
I take my hat off for your 315.000 km. I wouldn’t be surprised if you have driven more miles in an Ace than anybody else. I guess I have done roughly 20.000 km all in all in 31.
Out of curiosity could I ask were you have done all these kilometres?
Thanks for answering my questions. I really don’t think that there is anything very wrong with my steering box. So by fine tuning everything I hope to reach an acceptable result.
I will recheck the idler again.
Talking about the handbook I also believe it says that the steering when properly adjusted should be “finger light”, I wonder if anybody has experienced that!
Thanks again for helping out.
All the best.
Jonas
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Hi Jonas,
my mileage is all in The British Isles, furthest North being Orkney. Previous owners had borrowed the Bristol Overseas kit from Thames Ditton on occasion so it has been to Europe, I assume. When I bought it, it was just a stepping stone but somehow the cars character and Bristol exhaust note made it a constant companion for work, holidays, shopping, fishing trips.......
It should say "with wishbones supported and wheels in the air" don't you think.
Happy Motoring
Ron
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Jonas
A very interesting thread. I feel I have a number of observations, comments and suggestions to make but am restrained by the fact that I don't understand the question. What is tracking? Is it what I would describe as directional instability? Can you be more specific? I should add that over the past 50+ years I have owned four AC's - three Aceca Bristols and a 428 but know nothing about 'tracking at high speed'. My current Aceca Bristol is 33 JPD which was the factory demonstrator from 1959 to 1961 and was road tested by Autocar (8 April 1960). Their report said the steering was 'direct and precise but heavy at low speeds - tiring to manouvre' - we know what they meant ( on Michelin X tyres). Autocar also said that ' at near maximum speeds, the front of the car started to weave on crossing the central ridge between areas of concrete.... noted with other fast cars .... ceased almost immediately....without any action on the part of the driver. Is this a clue to your tracking at high speed? And how high? Autocar got 116 mph out of my car but I've never been near that!
Michael
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Michael,
Thanks for replying. I indeed mean directional instability, or maybe even that the car wants to “self steer” to some degree. It has gotten a bit better after I have adjusted the angle of the steering arm vis-à-vis the steering box and I also had a bush in the idler that protruded some thousands of an inch, but all that is now corrected.
So when I go faster, say above 60-65 mph I still experience a little bit of this, and that’s basically as fast as I go these days, but it would be nice to do 75-80. As I think I mentioned earlier in this thread I have had 31 for many years now and before I took it off the road in 2005 to start a restoration I used to regularly go almost flat out, say 90-95 mph and never think twice about the steering having a life of its own.
One thought I have is that the most recent Michelin X’s are different compared to the older ones, that could make a difference. Another thought is that the toe should be more pronounced and lastly I’m also wondering if my wheels are well balanced enough. I have checked the two last things at a tire shop and the digital readings are correct for both toe in and the balance of the tyres.
Sorry for the rambling but interesting to hear what other members of the forum thinks.
Thanks
Jonas
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Jonas
If you are going to solve your problem you have to start from a baseline of certainties. I presume you are satisfied that bearings, king pins and bushes,all suspension bushes, ball joints, rear end (the tail not wagging the dog) and steering box (come back to that) are all OK.
Tyres - I have no knowledge about how current Michelin X compare with those of 60 years ago. I have always thought Michelin are expensive but are the best. I think that tyres are not an issue, but what tyre pressures are you running? AC standard (normal) were F22/R24. I think for high speed you could go to 28/32. Might be worth trying, say, 26/29 to see if pressures have an effect.
Wheel geometry - AC figures are castor 5, camber 1 to 2 positive, KPI 9 and static toe-in 1/16 inch. Castor 3 to 4 is a bit short of 5 but I would settle for that unless all else fails. You haven't mentioned cambers but these can be measured accurately enough on a DIY basis with a spirit level (my method on application). Since stub axle and king pin trunnions are one machined part it follows that if cambers are OK then KPI's will be OK.
Now to static toe-in. The principle is that, when driving, rolling resistance at the tyres will 'pull them back' so they become parallel and roll true without generating slip angles when driving straight ahead. I guess you took the car to your local wheel alignment shop to have the toe-in set. 1/16 toe-in can be restated as 1/32 and angle A at each wheel. You state A as 0.25 degrees. I don't agree. My calculation is that A = 0.1 degrees. (Since you ask - rim lip to lip diameter = 17 and 3/8 inches. A=1/32 divided by 17.375 radians = 0.001798 radians = 0.001798 x 360/ 2pi degrees = 0.1 degrees.) So the question is whether the toe-in is set at 1/16 or 0.25 at each wheel? If the former why did 0.25 come in to the conversation? If the latter my calculation suggests you have 5/32 toe-in which is too much by a factor of 2.5. I think this (?) error, apart from producing transverse 'feathering' of the tyre treads, would be significant at high speeds.
To check whether the toe-in is OK you don't want to spend months and miles examining the treads for feathering. I suggest a wheel alignment gauge which gives an instant answer. I have a Gunson Trakrite which I recommend. It detects the transverse force arising from slip angle. (Happy to lend you mine but Malmo is not just down the road from Hampshire). You put the Gunson ahead of one front wheel, drive the car gently over it and your assistant sees the pointer showing OK, to much toe-in or too little toe-in. (Advice : Don't ask her when she is busy cooking a nice dinner for you). Incidentally, the other wheel rolls true without slip angle on your workshop floor and any misalignment when the car is driven shows up on the wheel going over the Gunson. If the Gunson does not show OK it's trial and error adjustment until it does show OK, but each test only takes minutes. I guess the cost of a Gunson is about the same as a visit to your alignment shop or, if they 'messed up' with the 0.25, nil after a full refund.
You should check the spring mounting bolts are tight. A broken leaf would be obvious but over time the spring can flatten. I wouldn't think it would at 80,000km and am not sure what the effect of flattening is.
Now to the steering box - your first but my last resort. Let's get the terminology right. We all have a Bishop cam and peg box. The bit inside which turns is not a worm which has a uniform cross section along its axial lenghth. I quote from my Automobile Engineer's Reference Book (1959). ''A truncated conical peg pressed into the rocker shaft engages a cam of varying depth. The method of manufacture of the cam involves a finishing operation by a cutter of the same form and rotating on the same axis as the peg. This cutter also moves through the same arcuate path as the peg and by so doing ensures uniform contact between the peg and cam. Slight clearance is allowed on the full lock positions to cover adjustment which may be necessary for concentrated wear at straight ahead.'' So, complicated machining.
I have known Barrie Bird for many years and regard him as the authority in all matters AC. However he said above 'the cam is machined to give more clearance in the straight ahead area'. This is wrong as Barrie, on reflection, will confirm. Just goes to show that elderly folk like us get confused sometimes. Steering box adjustment is delicate, particularly as things can change as you tighten the locknut. You must follow the procedure set out in the AC instructions. In spite of references to 'slightest drag' and 'no lost motion' I would aim to have very slight free play at straight ahead - say 1/8 inch at the steering wheel rim. Unless your steering box has been abused ( eg lack of oil or faulty adjustment) it should be good for many more miles. I wouldn't change the peg at this stage without clear evidence - maybe later if all else fails. You should check the steering box mounting bolts going through the aluminium block but note the warning in the AC instructions not to 'overtighten' them. However they didn't tell us how tight is too tight.
I picked up a warning signal when you said 'the peg is past the centre of the cam in the straight ahead position'. You later say you have adjusted the angle of the steering arm relative to the box. The only adjustment I know is to pull the drop arm off its splines and replace it on different splines. Sounds like you have got this right. In straight ahead the idler should be on the car centre line, the drop arm should be parallel to it and the steering wheel should have the same number of turns to the left and right full lock stops.
I hope some of this will be helpful. Good luck and remember the Golden Rule - only change one thing at a time.
If any of you are still reading this I have a question. Years ago the club did a batch of bracing struts to go diagonally from the steering box to the suspension tower. I have always thought that the steering box mounting was a bit 'flimsy' and bought a kit but never fitted it. My current Aceca (ex factory demonstrator) has an identical bracing strut fitted. I have never seen this referred to as a factory option. I wonder if AC fitted it after the Autocar reference to high speed wander or or was it out of the club batch and fitter by a subsequent owner? Now here's the interesting bit - my memory is that Barrie was the instigator of the club batch but I can't remember what the claimed benifit was. So, Barrie, if you are reading this do you plead 'guilty' and can you remember the intended benefit and whether the strut delivered it? Subject to Barrie enlightening us about bracing struts, perhaps this is what you, and maybe every owner, should have.
Michael
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Michael. & Jonas
Steering Box Steady Control Arm
A very in depth interesting analysis, You are definitely right , change one thing at a time.
You mention in your last paragraph " Steering Box Steady Control Arm " ..........These are available from:
Classic Autos Ltd
10, High Street.
Kings Langley.
Hertfordshire.
WD4 8HB
England
Tel: 01923 262994
Aubrey or Nik Finsburgh
PLEASE NOTE: They are handed, You must state Left Hand Drive or Right Hand Drive. ;)
I supplied Classic Autos with a full size drawing after I ordered mine, as I was incorrectly supplied a RHD unit
for my LHD BEX333.
I bought and fitted mine to BEX333 some 20 years ago, it definitely Supports the steering box. :)
Hope you solve your Steering Box problem.
Keith
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Michael,
Thank you very much for sharing your thoughts and experience in this matter, much appreciated. I also thank you for the kind offer to use your Trackrite. I am somewhat confident that the bearings, king pins and bushes, all suspension bushes, ball joints and steering box are fine since most parts are more or less “new”.
I will give you some more data about the Wheel geometry, well the caster is a little bit off as I think I mentioned 4 degrees and 02 minute degrees on the left and 3 degrees and 42 minute degrees on the right side. So 18 minute degrees difference, if that is too much I don’t know.
The camber on my car was at least – 23 minute degrees on the left and - 10 minute degrees on the right side; again if this is acceptable or not I don’t know but I have seen a couple of Ace’s that race that are set up with negative camber.
When it comes to the toe-in I have made the assumption (right or wrong?) that when the handbook states 1/16 toe-in that is per side, so my calculation is that the total toe-in should be 1/8 inches. I recently bought a Track ace alignment gauge, http://www.trackace.co.uk/ and when I use their guide to converting the 1/8 to degrees I end up with a total toe-in of 27 minute degrees.
So to answer your question where the 0.25 comes from it’s from the fact that I used to have the total toe-in set to 0.25 degrees. After trying this, which I believe corresponds to the factory specification, I have increased that to, at the wheel alignment shop 47 minute degrees, and when I measure it at my workshop with the Track ace, it’s roughly 40 minute degrees. I increased this after consulting with people with a lot more experience than me. When looking at the recommended toe-in for other English sports cars of the same era with 15 and 16 inch wheels, many of them seem to have a recommended total toe-in of 1/8 inches.
Anybody else out there with any ideas about this?
I very much regret that I didn’t check what toe-in 31 had before I pulled everything apart since it used to be less prone to high speed wander.
Furthermore what I meant about the angle of the steering arm relative to the box was that the arm, which I believe should be 3 degrees to the right, on a left hand drive car. If you look closely at the drawing in the handbook you can see that the arm is not straight in comparison with the column when in the dead ahead position. I’ve enclosed an image of a TR 3 steering box as well as the image from the handbook.
I do have a bracing strut that I have had for a very long time, I maybe got it when I had AE 25 in the early 1980’s but so far I haven’t fitted it, maybe I should?!
Thanks a lot for all the comments and help.
Jonas
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Jonas
You are right about the 3 degrees on the drop arm. The AC drawing you posted is identical to the one in my Service Instructions and my guess is that AC fitted the same box to left and right hand drive cars. I have measured 3 degrees on the AC drawing and the TR one is explicit in this respect. I wonder whether Triumph and AC independently specified this or did they take standard Burman boxes as supplied in large quantities to Austin for (was it?) A40's. On my car the drop arm poking out from under the box 'looks' parallel to the centre line but I couldn't detect 3 degrees by eye. If the drop arm was on the wrong splines (you talked of 'adjustment') this would move the arm by 15 degrees or so per spline which would be obvious. So please correct my statement to 'parallel or thereabouts'. In my view this is not relevant to high speed wander.
Now to castor and camber. I think the fact that you have about the same figures on both sides is more important than the variances from the AC figures. I think your figures will be fine and I don't think the variances are relevant to high speed wander. We don't know how 'sophisticated' the AC chassis jig was. Perhaps every car has different wheel geometry and maybe no two cars are identical. Has anybody got info on this?
Now to toe-in which I think is relevant to high speed wander.
1. Toe-in is not a design calculation. It reflects a concensus view that for rear wheel drive cars 1/16 to 1/8 toe-in will achieve the desired result which I stated as ' driving straight ahead / wheels parallel / rolling 'true' / no slip angles'.
2. Definition - I believe AC's 1/16 is on the basis of the classic definition ' Distance between the rims at hub height behind the hubs less the corresponding distance ahead of the hubs'. On that basis 1/16 is 'total' and not at each wheel. You interpreted AC's 1/16 as 1/8 total - this is wrong.
3. I have no knowlwdge of current alignment kit. Probably use mirrors and laser beams (whatever they are). From what you have told us I understand that the desired toe-in is converted to an angular toe-in at each wheel. The track rods are then adjusted to give this angular toe-in at each wheel.
4. I said that AC's 1/16 could be restated as 1/32 and angle A at each wheel. I set out my calculation that 1/16 toe-in on 16 inch wheels equates to an angle A at each wheel of 0.1 degrees. Now this is important : do you agree with my calculation? If you do we can 'scale' it up for other toe-ins and angles. If not, I think we are wasting our time discussing the matter.
5. You told us that '31 is set up with roughly 0.25 degrees per side which should equate with the 1/16 which it says in the handbook'. You later told us you had increased A to 40' or 47' (say 0.75 degrees). My calculation showed that 1/16 toe-in (total) gave A = 0.1 degrees. Scaled up it gives A = 0.25 degrees as 5/32 toe-in. At A = 0.75 degrees it gives toe-in as 15/32 - almost 1/2 inch. If you are driving AEX31 with, give or take a bit, 1/2 inch toe-in I am not surprised that it wanders at high speed.
So to progress matters we need to agree, or not, the definition of toe-in as used by AC and my calculation of the relation between toe-in and angle A at each wheel. Jason, I want to help you - AEX31 is an important car. An early Ace, the first one exported and the first LHD one isn't it? I hope the above doesn't sound confrontational but unless we agree the basics we will end up floundering about in a 'soup' of numbers. If we can agree the basics I am happy to advise you further and you are free to act on or ignore my advice. The important thing is that, in spite of the problems the club is facing, members and owners of our lovely AC cars continue to talk to and try to help each other.
Michael
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Here's another bit of background. My car was supplied by Rudds; it was on Michelin X when I bought it in 69 and the handbook had a pencil note on the useful information page saying - Rudd recommends 28, 26 tyre pressures. Seems fine to me, whatever tyres.
Cheers
Ron
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Michael,
Again thank you for taking time to engage in this matter. I’m in no way offended. My main reason for posting on the forum in the first place was to find out what to-in other Ace drivers
have and if anybody else has had experienced any similar problems.
Let me also try to be clearer with what I meant concerning the degrees of the drop arm. What I did was to adjust the length of the arm that goes from the steering arm
to the idler, so that the peg in the box was dead centre when the idler was, since it wasn’t!
To answer your question I have, as you know, made the assumption that the 1/16 toe-in as stated in the handbook, is per wheel since it states rim, not rims.
This might very well be a mistake on my part and this will obviously make a difference. I also have to admit that I was unclear in my previous post, I was and I am talking about the total toe-in,
i.e. the combined toe-in for both wheels.
I have since my last post talked with two AC Ace knowledgeable people and they have interpreted the handbook toe-in as referring to one wheel, when the 1/16 inch measurement is given.
But they can naturally have interpreted this wrongly. It would in this situation be interesting to hear how other members on the forum interprets the 1/16 inch toe-in statement;
if they believe it is per side, or the total toe-in?
I agree with your calculation under the fourth point, when I look at conversion tables for 16 inch wheels, from inches to degrees, 1/16 inches translates to 13 minute degrees which
is very close to 0.1 degrees.
At the moment 31 has a total toe-in of roughly 40 minute degrees, or 0,4 degrees which is too much regardless of how the handbook is interpreted. So I will definitely set the car up
with less to-in, after which I will post my experience of this.
One comment I have had during this “investigation” was that a problem could come from the fact that I’m using Penrite’s Semi fluid Steering Box lube and not a high viscosity oil…
I also feel I have to point out that I’m not an engineer, so any statement I make can obviously be wrong, I hope that that any possible ignorance on my part isn’t regarded as rudeness
since that’s the opposite of what I intended. I totally agree and hope that members and owners of AC cars will continue to talk to and try to help each other out as much as possible.
I am very grateful for all the comments and help I have received in this matter, as well as on other questions I have posted on the forum over the years.
Thanks also to Ron, the tyre pressure you stated is exactly what I have so that shouldn’t be the culprit!
Jonas
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Michael and Jonas,
My apologies for a long pause in contributing to this essential topic. My poor defence being the hours I am wasting on setting up a new lap top, demonstrating my ignorance of all things digital.
To begin with, when reading Michael Trotter's posts, I realise what a chasm exists between a proper engineer, like Michael and an amateur fitter, like me. Thus I have no doubt that my opinion on the clearance of cam to peg is quite wrong and the cam is machined with more clearance on lock as compared to straight ahead. Which being the case I am now puzzled by the too often observed, incorrectly adjusted Bishop Cam steering box, binding as lock is applied. In my experience there is a tendency, during adjustment, to reduce straight ahead free play too much and this seems always to result in the peg binding in the cam as the rocker arm travels from the straight ahead position. This prevents the self centering action of the caster angle operating and makes your Ace or Aceca an absolute pig to drive....
To address the specific problem described by Jonas, one of the symptoms of excessive toe in is poor straight line stability. If, as Michael suggests, this is the situation with AEX 31 then it will be interesting to hear the results of a revision to the toe in adjustment.
Turning to the general question of toe in I used a tracking pad for many years, such as Michael describes, but eventually concluded that the drag due to tyre rolling resistance probably varied as the square of speed and any slip angle detected at walking pace might be misleading at sixty or seventy miles an hour. The other doubt in my mind was repeatability, or rather the lack of it: Slip angles measured on each run seemed to have quite a large scatter. I now use the 'Trackace' system mentioned by Jonas. The other thing about the effects of drag on front wheel alignment concerns the early versus the later Ace chassis: The early cars, including '31, have hard mounts for the inner wishbone whilst the later car uses rubber bushes which one might suppose give greater compliance. As far as I am aware the toe in setting remained the same for both when you might expect the early 'solid' wishbone to require less toe in angle ?
Jonas mentions choice of steering box oil and I don't believe that this will have any effect on straight line stability. In the interests of longevity I use a synthetic gear oil - Mobil SHC 75W - 90, but I'm sure his Penrite is satisfactory.
Steering box brace: It was not me that was involved in a batch, but I have made a couple for myself. I remember David Sanderson telling me that the LHD Ace steering box mount is far less rigid than the RHD mount and I think the steering brace requirement could have come from SCCA racing. Whatever the instigation you can't have too much of a good thing so braces all round - RHD and LHD. However I doubt that the brace would affect straight line stability as any flexing would be more likely during brisk cornering.
Finally (sigh of relief) I am wondering about some of the calculations shewn in this thread. Mixing fractions of a degree with decimal points is not a good idea. It does seem to be the modern way, but 2.5° is not 2° 50' it is 2° 30' . On this basis '31 with 40' of toe in (0.66°) then it is over 3/16 of an inch
Barrie
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Barrie,
Thanks for your comments. First I have to admit to being guilty of mixing up fractions of a degree with decimal points. I’m aware of the difference, and I did try not to make this mistake, but I did. Sorry.
Since I’m travelling at the moment I haven’t had a chance to set the toe-in to lesser degrees.
However I’m still wondering what the verdict is concerning the statement in the handbook, is 1/16 intended as the overall toe-in or is it per wheel?
I’ve also enclosed the Track-ace conversion table which is what I have used as a base to decipher what the setting 31 has.
Thanks Jonas
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Jonas,
Who knows what was in the author's mind when the original 1/16" was specified ? In any event I think Michael has a very persuasive argument that A.C. meant total total toe in. In addition that dimension is not a critical, engineering law of physics: It is really an arbitrary guess - if manufacturing teams thought that their suspensions would drag back to the tune of 1/16" toe out then best start off with 1/16" toe in. I doubt there was much calibrated testing carried out in the early days, but by experiment and experience manufacturers came to recommend a static toe in figure. There is no reason why you and your highly accurate Trackace cannot do the same thing, coupled with your assessment as a driver and an observation of tyre wear patterns. So I would start off at 1/16" total toe in and then see how she drives and how the tyres wear.
The nice thing about having the Trackace is knowing exactly where you are with these adjustments - once you have got a satisfactory setting of toe in you can return to it with great accuracy.
Do let us know what you discover, I will need to set the toe in on '22 shortly
Barrie
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I'm with you on that Barry, try 1/16" total toe in at the front and see how that feels. I normally run parallel at the back on an Ace and a gnat's of toe out on the Cobra.
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Jonas
You say you are still 'wondering what the verdict is ' re AC's 'Toe-in 1/16 inch' - did they mean total or per wheel? I set out above what I described as the classic definition of toe-in. The same definition appears in my Automobile Engineers Reference Book (1959, edited by George Lanchester) and in 'Racing and Sports Car Chassis Design' (1965, by Costin and Phipps). I regard both as authoritive and both are 'in period'. I cannot believe AC did not follow the convention of the day- ie 1/16 was total.
I worked through your Trackace chart 'Converting mm to degrees' starting with 1/16 inch and 16 inch wheels and got the result 13 minutes at each wheel. Given their roundings this is twice my calculated 0.1 degrees (6 minutes) so I deduce they are using mm toe-in per wheel. Do they make any reference to total / each wheel toe-in? It may be that with mirrors and laser beams the definition has changed but current usage is not relavent to your question.
I hope you will set 0.1 degrees toe-in at each wheel. Note Barrie's correction : 1 degree = 60 minutes and not 100 which you appear to use. So my 0.1 degrees = 6 minutes.
I look forward to your next report - we all hope you will eliminate the dreaded 'tracking'.
Michael
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Toe in ( or out) is across the axle so for me all references are total.
I am sure the track ace measures total toe in/ out as it’s measuring one wheel relative to the other.( I have used a track ace since they came out).
Regardless of your tracking setting , the play in the box will dictate whether you control the car via the steering wheel or the road surface does the steering for you due to road surface changes and the play available to it.
I would Jack the car up and check ( with someone holding the steering wheel) how much slop you have at dead centre
My vintage 1929 Citroen had such an issue ( worm and sector) and it felt like I was driving a boat down the road.
Graham
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All,
This is a topic which grabbed my attention because I've always wondered if what I am experiencing with the original steering set up in my 1959 AC Aceca is normal. Note that my suspension has been rebuilt, including tie rod ends. I also have a Revington TR modified top plate installed on the top of my steering box. All of these things have helped tighten things up to some degree, but it seems there is still a lot of excessive play at the center position. In essence, I estimate to have about 5-1/2 inches of travel before I meet some moderate resistance in the steering wheel. The "highly technical" ;) photos attached demonstrate what I am experiencing. All this play makes going through the twisties somewhat challenging, particularly when changing directions quickly. Frankly, it's hard to imagine Aces dominating the race circuits back in the day with this kind of vague steering. I should also note that the steering box was out and I was told that there was nothing obviously worn but I am second guessing that. I've heard steering can be significantly improved by rotating the pin 90 degrees, exposing a fresh/unworn surface for it to engage with the sector. Would appreciate any thoughts on my what the photos are demonstrating, pin rotation as a solution, and/or anything else obvious to check.
Thanks,
Greg
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Dear all,
A sincere thank you all for joining in and helping out with the toe-in examination. It’s very pleasing that so many of you are sharing your technical knowledge of these lovely cars.
Michael, I do suspect that AC did follow the convention of the day so that 1/16 was the total toe-in. However I still find it interesting that it says “on rim”, that might very well be a linguistic detail that should be overlooked. As previously mentioned, other British sports cars of the period came with recommendations of a lot more toe-in.
Barrie, you most definitely make an interesting observation that the early cars have harder mounts for the inner wishbone. I believe I have the original handbook for 31 (that was delivered in the summer 1954) and that definitely states 1/16, as it does in later handbooks.
I’m just back from the UK so I will try to find time this week to set the toe-in to a total of 13’, or 1/16 of an inch, and test it! Hopefully with astonishing results.
Contrary to Greg’s experience I have to say that 31 is fantastic around winding roads, it’s only at higher speeds, on straight roads that the wandering manifests itself. The total play on 31, if doing Greg’s test would be, I’m guessing a maximum of 2 inches, if that.
Best regards
Jonas
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Dear Jonas,
Many thanks for providing some perspective as it relates to AEX 31. This is really good information to validate my suspicions that something is amiss with my steering setup.
If anyone else has any experience with pre and post pin replacement/rotation as it relates to steering play I would greatly appreciate it.
Thank you,
Greg
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To be consistent when comparing the steering wheel play test the steering wheel diameter needs stated as if you fitted a larger steering wheel the play ( although the same) will appear larger.
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Greg,
Looking at your photographs and reading about your steering woes I am left wondering what exactly the 'TR Revington' steering box top cover is ?
If, as I suspect, it is some kind of modification to introduce spring loading to the peg engagement with the cam then my view would be that your steering will never be right til you return the steering box to original Bishop Cam specification. If Bishop had wanted compliance in their system they would have included it: It would seem to me that their whole purpose was to eliminate compliance. Introducing any kind of compliance will appear at the steering wheel as excessive play.
Incidentally I should observe that when checking and setting play at the steering wheel rim only light force should be applied - the front wheels should not move nor the tyre sidewalls flex.
I find the steering system on the Ace, Aceca and Mk. I Cobra quick and accurate - threading the A.C. through a series of corners on a quite country road is a joy.
Barrie
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Gentlemen,
I finally managed to find time to reset the toe-in on 31 to 12-13 minute degrees, which should be the equivalent of 1/16 of an inch. I had planned to do a drive test yesterday but a torrential down poor ment that I had to spend yesterday afternoon looking after a bilge pump, and sweeping floors!
So this morning I eventually took the car out for a longer test drive. The steering behaved better than before so I’m convinced that 1/16 is for the total toe-in. The steering has open up a bit and at the same time straight ahead stability was better. I did take the car up to something like 125 kph, which is a bit more than 75 mph. My next careful adjustment has to be to adjust the peg “until the slightest drag is felt over the dead ahead position”. Any idea just how slight that should be, hardly noticeable or just a bit more?!
Great thanks to Michael, Berrie, Andy and everybody else that helped out with this.
Jonas
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Gentlemen,
The diameter of my steering wheel is just under 15" and the Revington modified top plate is, indeed, the type with a spring-loaded pin. I replaced the original top plate a number of years ago with the Revington version and, to my recollection, it did improve things a bit. I still retain the original top plate and will definitely have it available as I work to resolve the larger issue of considerably excessive play. Thank you for all of your comments. They have been very helpful.
Greg
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Greg,
One way to check if the play is due to an issue in your linkages (ie track rods) or the steering box is to jack up one wheel and check for play at the wheel that's jacked up (the steering wheel ought not to move as the wheel on the ground has it locked) followed by the other wheel (with side you just checked on terra firma). Assuming no play you can assume its in the steering box.
Graham
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Graham,
Thank you very much for the helpful suggestion. I will definitely perform this test.
Greg
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I am surprised no one discussed converting to rack and pinion. I did that on my Ace Bristol and it transformed the car. We use it for long distance rallies and it has been brilliant.
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Set up properly the Bishop Cam system is very effective and very quick. Going to a rack loses the quick ratio and originality: The former loses a great part of the car's character and the latter will decrease the car's value.
Barrie
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Good morning gentlemen
Jonas : I have learnt more about how Trackace works and understand their angle is the included angle betwen the two wheels - what we have been calling the 'total' angle, the sum of the two angles A at the two wheels. I am pleased to hear that AEX31 is now 'better' at higher speeds. It has been a bumpy ride to get there but if you followed the Trackace 'pre-measurement' procedure and have measured around my 12' or Trackace's 13' (what's 1' between friends?) I feel sure you now have the 1/16'' toe-in which AC decided was best for the Ace. However, I am surprised and concerned that you now tell us you have 2" free play at the wheel. Not sure whether you mean at the steering or road wheel, but in either case this is excessive and you must eliminate it to get your car driving as it should. Your question about 'slighest drag' implies that you think the free play is in the steering box. I cannot define slightest play. The danger in steering box adjustment is overtightening the screw. Hence my advice above to ignore 'slightest drag'. It is difficult to distinguish 'too much drag' and 'slightest drag' but easy to distinguish 'slightest drag' and 'slight free play'. Hence my advice to aim for slight free play, say 1/8 " at the steering wheel, which you will never notice when driving. I sense you are not entirely convinced about toe-in. Howabout finding a garage workshop with a 'drive over' alignment gauge to confirm it shows 'Toe-in OK'?
Greg : Your 5 and 1/2 inches of free play sounds to me frightening, indeed dangerous. I think it would, rightly, earn you an MOT failure. You need to identify the cause of the free play and I suggest : 1. Drive it into your workshop 'straight ahead'. 2. Have an assistant turn the steering wheel slowly and gently (finger and thumb only) through the free play telling you when the direction is reversed. You will be feeling the drop arm under the steering box. 3. If the drop arm moves throughout the free play your problem is not in the box but elsewhere and will be obvious or can be identified. 4. If the drop arm does not move at all your problem is only in the steering box. 5. If it moves partly you have a bit of both. 6. If, as I suspect, you have a steering box problem you have to question your Revington steering box cover plate. Like Barrie, I don't know the detail of it but, like him, I am suspicious of it and recommend that you replace it with the proper Burman cover plate with its adjustment screw. 7. Note my observations above re other relevant matters.
Jonas and Greg : If you think a conversation would be more helpful than exchange of posts here do give me a call.
Michael
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Jonas
I said above 'I cannot define slightest play'. I meant to say 'I cannot define slightest drag'. Just confirms, as I said earlier, elderly folk get confused sometimes. Talking of typos, they had them in 1954 when AC said 'on rim' but meant to say 'on rims'.
Michael
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Good afternoon gentlemen,
Thanks Michael for helping out again. I do also think that 1’ shouldn’t matter very much. I’m also rather certain that Track Ace isn’t accurate down to the last decimal!
I’m afraid that I do find myself rereading what I have written, and unfortunately conclude that I have been unclear, or not precise enough.
Sorry about that. Let me try to rectify that.
I did mean that the play was at the steering wheel. I redid the test and I now I tried to replicate Greg's test down to using a similar tape and ear swabs!
Since I perform this test on my own I basically move the steering wheel to either side until I feel, again, the slightest drag, or shall I say resistance in the steering wheel on either side.
I suppose I have to get an assistant so I can perform the drop arm test. Either way, when no applying any force at all the play in the steering wheel is not as much as I previously mentioned.
It’s something like 14-15 mm which is something in-between 9/16 and 5/8 of an inch, which is a whole lot more than the 1/8 you mentioned. Please see the attached images.
I do think that I have to perform the “drop arm test”, in hindsight; I should have done that a long time ago…
But, and I think this is important, do I understand you correctly Michael that I should aim for a free play of 1/8 at the steering wheel when adjusting the steering box?
Something that springs to mind is that the peg that goes into the worm on 31 was visibly compressed on the sides that moved against the worm. I did press it out, turned it 90 degrees before pressing it back on again…
I have asked around the “classic car circle” in southern Sweden and so far nobody has admitted to be in possession of a 'drive over' alignment gauge. I also have a feeling that the old Dunlop toe in gauges with two mirrors
are more accurate than the Track Ace version, they are also a lot more expensive!
So the quest for the optimal steering experience goes on.
Jonas
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All,
This string has been an eye opener for me in terms of confirming what I have suspected for the many years I have owned AEX734. The steering definitely has some issues. What's ironic is that I have simply grown accustomed to all the play. Initially, the play was simply attributed to the vague feel of the antiquated Bishop Cam box. Seeing my ear swab test duplicated (thank you, Jonas!) provides some quantifiable evidence that what I have been accepting all of these years is far from in spec! What's frustrating is that I recently had my car at a "reputable" shop in northern California for some unrelated work and I asked them to look at the steering box for wear. They pulled it apart, reported that all appeared okay, and proceeded to put it back together.
Yesterday evening, with the help of my wife turning the steering wheel, I performed the drop arm test. Sure enough, the drop arm remained fixed as my wife gently moved the wheel from side to side through its range of motion. More quantifiable evidence that something is amiss in the steering box. Very exciting stuff as I now know where to focus the attention! My first step will be to rotate the pin 90 degrees and see what kind of improvement results. As suggested here I will also remove the Revington top plate and replace it with the original plate, although I don't believe that is a contributing factor to all of the play.
Thanks very much to all who have contributed to this string as it has been incredibly helpful. I'll be sure to report back once the changes have been made to my steering.
Best regards,
Greg
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Greg,
This is from the UK M.O.T testing manual (annual vehicle check though many older cars exempt)-so 75mm for a 380mm diameter wheel.
You should be able to make a quick calculator in excel for different wheel diameters or mark your wheel with tape at the 380mm dia/190mm radius.
To check steering play:
Make sure the road wheels are on the ground and pointing straight ahead.
Lightly turn the steering wheel left and right as far as possible without moving the road wheels.
Check the amount of free play at the rim of the steering wheel.
If power steering is fitted, the engine must be running.
Steering wheel free play should not be more than:
13mm for rack and pinion steering, or 48mm if there are several joints between the steering wheel and the rack
75mm for non-rack and pinion
These limits are for a standard 380mm diameter steering wheel. The limits should be adjusted up or down accordingly with larger or smaller diameter steering wheels.
Play due to wear or maladjustment must not be confused with apparent play due to the construction of the mechanism, such as caused by the deflection of flexible joints or spring compression in external power steering systems.
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Jonas
Sorry for delay - tme flies!
I am confident that your toe-in is now what AC meant by 1/16" and that when you get rid of the free play at the steering wheel your car will drive as an Ace should. It sounds like you have owned AEX31 from new - very impressive. If you have not adjusted the steering box before, 80,000km sounds like a good time to do so. By the way, when I suggested a drive-over gauge I was thinking of the Volvo dealer or independent garages in Malmo.
Yes I did advise you to aim for slight free play, say 1/8", at the steering wheel. I should have advised AC's slightest drag and no free play. But that gives rise to your question and I cannot define slightest drag. It is many years since I adjusted a Burman box but my recollection is that it was tricky and sensitive. It was all about 'feel' and 'judgement'. I think the range from slight play to too much drag is covered by not many thou of axial movement of the screw. Hence the sensitivity and the locknut issue. AC in their instructions refer to adjustment as 'extremely critical' and emphasise that you must 'avoid excessive tightening of the adjustment screw' which brings us back to slightest drag.
My advice is to take your courage in your hands, select a screwdriver which is a good fit in the screw, have a go and experiment. Better to end up with slight play than with too much drag BUT slightest drag and no free play is the holy grail which you should aim for. Good luck and let us know how you get on.
Michael
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Michael,
Sorry for the delay in replying, I celebrated Bonfire Night in England! Thanks for your comments. The steering on 31 is another step closer to being as good as it can, I think!
I haven’t owned 31 since new but I have owned “the mistress”, as my wife calls her, for 23 years now. I did drive her a lot the first 6 years, and as far as I remember the steering box wasn’t touched at all in those 6 years. So I guess some previous owner or mechanic did indeed find that sweet spot or the perfect adjustment of the peg if you like.
I have used up a lot of courage this year when trying to find the exact spot where slightest drag and free play are in harmony. I have always adjusted the steering with the front wheels jacked up but I’ve also done very slight, road side adjustments which I believe has been helping me get closer to a good balance. I very much agree with you that the setting is very, very sensitive and that the difference in between a good and bad setting is very slight. I also have to say that after having adjusted “en route” to satisfactory result, checking afterwards with the front wheels up gives me more than a feeling of slightest drag…
Jonas
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Good morning Jonas
When you started this topic in June you were seeking a replacement steering box. A month later (#11) you told us 'I don't think there is anything very wrong with my steering box'. Was this a change of mind about the original or were you talking about a replacement? I hope the former as the latter might well have cost you a lot in time and cash for a box no better than your original low-mileage one. You reduced the toe-in from 5/32" or more to 1/16". I hope you noted my reservation re following Trackace pre-measurement procedure. I shall be more confident when you have taken AEX31 to a drive-over gauge which shows it spot-on. You reported (#32) that 'the steering and stability were better' but, presumably not as good as you hoped for, since you said you would then adjust the steering box. Later (#44) you say you have been adjusting it over time and it is disappointing that you still have 14 or 15 mm free play which is no good. I feel cautious about assuming , as I think you do, that better adjustment will get you to slightest drag and no free play and the instability problem will be completely cured.
Forgive me for being blunt but I think you need to bring to your instability / steering box problems clarity of thought and decisive action as dished out by Napoleon. He always had a battle plan - only failed once near a village in Belgium called Waterloo. Firstly I advise you to carry out the procedure (the 'drop arm test') which I suggested to Greg (wonder how he is getting on). This will confirm whether or not the free play is all a steering box issue. Note this test only provides evidence about the box and the linkage. It will tell you nothing about the bearings, king pins, suspension bushes etc. which I listed (#15) as 'baseline certainties', being factors which could contribute to instability. You said you were 'somewhat confident these were all fine'. You may need to reconsider this later if you think the stability is not as good as as it should be.
Now to the steering box. I suggest the following: 1. We haven't mentioned the possibility of axial movement of the cam - unlikely but best be sure. Push the wheel towards the dash and then pull away from the dash. There should be no axial movement of the column. If there is the box must be re-shimmed before adjustment. 2. Do not waste your time adjusting it at the side of the road - follow AC's instructions. 3. Experiment and get used to the feelings of drag - nil, slightest, slight and too much. This is not adjusting. It is getting a 'feel' for different drags and the relation of movement of the screw and the resulting effect on drag. 4.If you despair of distinguishing different degrees of drag I suggest you separate the drop arm / draglink ball joint and tie up the draglink out of the way. This will eliminate the background drag from the balljoints, idler and king pins. This drag should be little (but when did you last grease them?). You will now only feel peg to cam drag and can continue with the wheels on the floor. 5. Repeat 3 above if you have done 4 above. 6. Now to adjustment. When you you have slightest drag hold the screw with your best screwdriver and tighten the locknut. 7. If, as I expect, the drag has changed your knowledge of the feel of drags and the related rotation of the screw will tell you the direction and extent of the change. Re-adjust with an allowance for the 'locknut effect'. 8. It may take several trial and error re-adjustments but by lunchtime you will have got the hang of this Burman lark and have slightest drag and no free play. If all else fails, slight free play is better than too much drag. 9. Remember to refit the ball joint!
I hope your further reports will tell us that AEX31 now drives as well as it did when it left that little factory in Thames Ditton 68 years ago.
Michael
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Jonas
A footnote to my above post. I expect you realised, but I forgot to remind you that the column/cam axial check must be done with the wheels off the floor.
Michael
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Michael,
Thank you for your continued contributions to this thread. I did the drop arm test a while back and, from what I can tell, my grossly abundant free play is related to the steering box. Since performing this test weeks ago, I've simply been waiting for my turn with my busy mechanic. Seeing your most recent post regarding the axial check, I performed that test today and noted no axial play. I will be sure to report back once the steering box is evaluated.
Greg
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Dear Michael,
Again thanks for your valued input concerning the steering of our beloved Ace’s and Aceca’s. The first snow has fallen in southern Sweden so I fear any more driving, and testing will have to wait until spring is here.
I think that you in a very clear and systematic way put light on the importance of being thorough and meticulous when trying to find out a mechanical problem. I will certainly start over from “scratch” when the temperature allows.
To answer some of your questions I have carried out a number of the procedures that you suggest and the results have all seemed satisfactory. But since I’m taking the track rods off the car soon for repainting, I will have the opportunity to go about this in a precise way when reassembling again.
I haven’t tried or tested the column/cam for axial birthday lay since the box was restored by a professional, but I will do this as soon as have time and I will post my findings.
On a slightly different note I would argue that Napoleon did loose big time at the battle of Leipzig in 1813. Important as a Swede since this was the last time Sweden was at war on the continent, but Napoleon did indeed have a battle plan!
Thanks again from at the moment a white Copenhagen.
Jonas
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All,
I had some further delays to getting my car to my mechanic so I ended up pulling the sector shaft myself. The most difficult part was finding a suitable puller to engage with the angled "ears" on the drag link. The shaft seems to be in good shape and to the naked eye and fingers the pin seemed unworn. I did, however, devise a rather crude way to check wear on the pin by stacking washers incrementally and measuring with my micrometer at each level and did note a small amount of wear. It's hard to believe the fractional amount could amount to much play but I'm going to have the pin turned 90 degrees just the same. Here are my findings:
Wear sides
Base = 13.88mm
1 washer = 11.88mm
2 washers = 10.80mm
3 washers = 10.24mm
90 degrees to wear sides
Base = 13.90mm
1 washer = 12.02mm
2 washers = 10.92 mm
3 washers = 10.28mm
I think I will ultimately remove the steering assembly for rebuild. Checking my tattered AC manual, it states that the offside shock absorber must be removed. I've not had any experience with this. Are there any precautions to take into consideration? Don't want a loaded spring/shock to release suddenly and cause an issue.
Thanks in advance for any advice on this,
Greg
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Good morning Greg
Impressed by your measurements of the peg. You have identified slight wear (a bit over 5 thou on diameter) and there will be corresponding slight but acceptable wear on the cam. Just as Bishop expected and for which they provided compensating adjustment. You will rotate the peg which will have long-term benefit but will not, I think , do much for 5"+ of free play. You say the shaft looks fine and diameter measurements would confirm this.
You are now intending to remove the steering box to 'rebuild' it. The implication is that you are of the opinion that the cause of the free play is in the steering box rather than in the adjustment of it. But where is the evidence? No opinion is worth holding unless it is supported by evidence. The only evidence I am aware of is your confirmation of no axial movement of the column (hope you had the wheels off the floor). This suggests there is nothing much wrong with the cam/column assembly, the upper and lower bearings or the shimming. Now this is not decisive evidence but it is negative rather than positive and supporting your opinion. And what would a rebuild involve? A new cam and new bearings? Hardly 'off the shelf' stuff. I think Jonas may have researched this, or have knowledge, and his advice would be helpful. I have in mind a lot of time, a lot of dollars and replacement parts of questionable quality. Sounds to me like a high cost to benefit ratio. But it is your car, your time and your cash..........
And what about adjustment? Seems to have gone out of the window. With respect Greg, I think you are going the wrong way at the fork in the road. If I were you I would refit the rocker shaft in the straight ahead position, crank and peg at 90 degrees to the axis of the cam. No need to replace the drop arm at this stage. Fit the Bishop cover plate and adjust the box, wheels on the floor. Somebody banged on about this at great length above. Only if careful adjustment failed to eliminate the free play would I think 'rebuild'. If you take the other road at the fork - rebuild, fit the Bishop cover, adjust and eliminate free play you will never know whether all those dollars were wasted and you will have concerns, perhaps, about the quality of the replacement parts. If you doubt the wisdom of my advice, ask your wife for her opinion as she is clearly a member of 'Team 59 Aceca'.
Now, to cut to the chase (I do go on a bit). You asked for advice about removing the steering box. Unless you have evidence (sufficient, relevant and reliable) that it is broke don't fix it. My advice is to leave the steering box where it is and adjust it.
By the way, I take issue with your description of the Burman steering box as 'antiquated' (OED = old fashioned, out of date). It was good British engineering in the 1950's and still is in 2023. (Pause for 'Rule Britannia'!)
Regards and a Happy New Year to you. May 2023 be the year you get your Aceca steering safely, indeed as it did ex-Thames Ditton in 1959.
Michael
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Greg
For 'Burman' read 'Bishop' !
Michael
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Dear Michael (and all),
First, thank you for your comments and suggestions. Some interesting developments to share... After a referral and a couple of additional phone calls, I was able to find someone to rotate the pin on the sector shaft 90 degrees. It was mere minutes from when I explained what I wanted to have done to when it was brought back out to me with the operation completed. After a quick back and forth between the brothers that owned the shop, it was handed back to me at no charge. I returned their generosity with a couple of bottles of wine later that day and everyone was happy (Merry Christmas to all).
I had every intention of pulling the steering box assembly for rebuilding but first wanted to see what effect, if any, the rotated pin would have. During the Christmas Holiday, and with the help of a friend, I reinstalled the sector shaft and put the original top plate back into service. We initially lowered the adjustment screw only checking the slightest side to side motion on the steering wheel for drag but quickly discovered that things tightened up considerably when the wheels were turned much more than that so we jacked up the front end of the car, made some additional adjustments which allowed the wheels to more comfortably achieve lock in either direction, and went for a ride. What's odd is that the alignment seemed off, with the car pulling a little to the right. Looking at the wheels, it seems as though the right front wheel is turned out slightly. This has me scratching my head because, other than rotating the pin, nothing was done to the tie rods. I need to look into this further and I also want to look at some further fiddling with the pin adjustment screw depth. What's really interesting what has happened to the free play. It's gone from 5+ inches down to 1 inch or maybe 1.5 inches (see attached official Q-tip test photos). And looking at the drag link arm when the steering wheel is being rotated shows immediate movement of the sector shaft, with that 1 to 1.5 inches of free play being absorbed into the steering linkage. Amazing! Needless to say I don't have any plans to pull the steering box assembly now. Could the alignment have been thrown off by things tightening up so much? You would think that any effect would have been uniform given the whole steering linkage is locked together. Regardless, I'm hoping a trip to the alignment shop solves things. More to come once our much-needed California rains subside.
Best,
Greg
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Good morning Greg
Pleased to hear that Plan B is progressing - I think you are well on the way. Not entirely clear to me but I think you have eliminated the 4" of free play coming from the steering box and are left with 1"+ coming from ahead of the drop arm. Greg, I am not writing a workshop manual - I just make this stuff up as I go along. However, as you would expect, I have some observations which you may find helpful.
1. A full repeat of my 'drop arm test' should confirm that 1"+ is nothing to do with the steering box but comes from beyond the drop arm. 2. Your description of the RH front wheel sounds like toe-out. This will not have happened overnight but will have been lost in the excessive play. Probably arises from the cause of the 1"+. Driving a few feet in reverse may change this 'alignment'. 3. Don't rush to your alignment shop. When you have got rid of the 1"+ you will want an alignment check then (12 to 13 minutes included angle between the wheels - 12.37 to be exact). 4. Read all the above in this thread and note what is relevant to you. 5. A word of caution. The danger in adjusting is overtightening the screw. You may have done this in trying to get rid of the last of the free play. When you have got rid of the 1"+ I think you should follow in detail the AC adjustment instructions. Back off the screw and go through the full procedure, noting that 1/8" free play is better than too much drag at straight ahead. Check for free, easy movement lock to lock with increasing free play away from straight ahead.
I think you are nearly there but let me know if you have problems/questions. Keep me posted on your further progress - I feel a personal involvement and will not be satisfied until you can report 'rock steady at 100mph' (you pay for the speeding ticket!).
Michael
P.S. Do you think the mileage (?88,000) is genuine and what is the chassis number?
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I live in the same town as Greg and have been at his house a few times to help sort out his steering woes. When I heard that rotating the peg 90 degrees (to the virgin side of the peg) eliminated most of the 5 inches of play at the steering wheel, I had to get my head around how this could be… Being an engineer, I drafted the attached exhibit in CAD to illustrate the relationship between 5 inches of play at the steering wheel vs. the travel of the worm drive at the peg. Pretty simple geometry here…”a picture is worth s thousand words”. Based on the exhibit, you can see that the worm drive (groove that the peg rides in) only has to move 1/4 inch in each direction (1/2 inch total) to account for 5 inches of play at the wheel. I guess that the wear on the peg accounts for most of this movement.
I hope this helps everyone visualize the situation better.
John
AEX521
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Greg and John - Good morning
John : Liked your drawing and I agree all the data therein. Not so keen on the title - we don't have worms in our steering boxes (see my #15 above). Just pulling your leg and reminding you that pedantry is alive and well and living in Hampshire UK! Perhaps another example of 'Two nations divided by a common language'?
As I understand it the 90 degree rotation of the peg and the replacement of the Revington cover with the (adjusted) Bishop cover combined gave a 4" reduction in free play at the steering wheel. You say 'I guess the wear on the peg accounts for most of this movement'. My guess is at the other end of the range and I estimate that about 1/4" of the reduction is attributable to the peg rotation and the rest of the 4" is attributable to the Bishop cover.
Greg : Hope you have not been affected by the flooding in California. I have to apologise to you. I led you into breaking the Golden Rule - only change one thing at a time. If you want to add to the body of AC knowledge you could refit the Revington cover and see how much the rotated peg alone does for the original 5"+ free play. Wouldn't take long and wouldn't affect the current Bishop adjustment setting.
Now to the remaining 1"+ of free play. As I have said I think this comes from the linkage ahead of the drop arm (think six balljoints and the idler for starters). A careful repeat of my drop arm test should confirm or deny this. 'Looking at' and 'Starting to move' is relevant, but not reliable, evidence.
With our different terminologies we get into tom'ay'to / tom'ar'to territory as the song goes. But we both are lucky enough to own 1959 Acecas and want them to drive as they should.
Michael
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Good morning Jonas and Greg
Jonas : The Times today tells me that yesterday Copenhagen was 14C and sunny. Have you been able to get AEX31 out on the road again? And you were quite right about the Battle of Leiptzig!
Greg : Long time, no hear. Have you been able to progress the elimination of that last 1"+ of free play at the steering wheel rim of your Aceca?
Michael
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Michael,
Even if I live in Malmö (Sweden) I’m actually in Copenhagen at the moment and I’m pleased to tell you that it is closer to 19 degrees, rather lovely!
I have done most of the things I set out to do with 31 over the winter but an electrical problem has made it impossible for me to try out the steering at any higher speeds. I am hopeful this can be cured soon so that I can report on progress regarding the steering.
Best regards
Jonas
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Dear all and especially Michael,
I’m sorry for my delay in replying but moving my office and other time consuming chores postponed high speed testing of the steering until this last weekend.
The result was very positive and the steering felt better than it ever has since 31 was restored some 6-7 years ago. I’m very sure now that 12-13 minute degrees in total toe-in is what it should be. I should also mention that I have gone through and adjusted all the steering components and I also changed the tie-rod ends to have the best possible preconditions. It did make a big difference.
Thanks to everybody, especially Michael, that’s been supportive and helpful in this process.
Best wishes
Jonas
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Good evening Jonas
Very pleased to hear that you have been able to do high speed testing of AEX31 and that it steers well and feels stable. Are we into 'rock solid at 100 mph' territory?
Regards
Michael
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Good morning Michael,
Well “rock solid” at 100 km/h possibly! I was out yesterday and was getting up to 120 km/h which would equate to 75 mph and that feels okay, maybe not rock solid though!
It would be interesting to hear from members on this forum and their experiences with front end stability at higher speeds? I also believe that the type of wheels and tyres, not to mention their condition (!) are important factors in how an Ace or Aceca behaves at higher speeds.
Something I’m interested to hear about is if there is anybody that has any experience with using Blockley tyres on an Ace? I have spoken to people that have used them on other cars from the same period that are very positive towards them.
Jonas
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Something I’m interested to hear about is if there is anybody that has any experience with using Blockley tyres on an Ace? I have spoken to people that have used them on other cars from the same period that are very positive towards them.
Hello Jonas,
I have been running Blockley Cross Ply tyres on my Ace for 5 years, in the standard 5.50x16" size. Although comparing them with the worn out Michelin X tyres that they replaced would not be completely fair, I have been very pleased with the Blockleys as they make for I think a very good handling and have made the steering feel lighter and more reponsive than it is. Mine are now certainly less sticky and a little harder than they were new but they still perform very well, at least for sparse road use. I have found a necessity to overinflate them when letting the car sit for several weeks in order to avoid flats, which take some driving getting rid of even on a light car like an Ace. This is perhaps their only drawback, though I guess all tyres suffer from flats on cars used not often enough.
A cosmetic plus for me is that Blockley Cross Plys have a wider sidewall and make the car look a bit more serious and grown up than with any of the other slimmer radial offerings that make the car look very dated, nearly with bicycle wheels.
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Hello,
Thank you for sharing your experiences about the Blockley tyres. As mentioned earlier I have heard of positive experiences about these tyres on other cars so glad that this is also the case when fitted on an Ace. Especially that it makes the steering feel lighter in comparison with old X’s, would you say that high speed stability is also improved? I have tried a number of different tyres and at the moment 31 is fitted with Excelsior 5.50 x 16 radial tyres that work okay but they are rather loud over 50-60 mph.
By the way, could I ask you if your car an early or later car with rubber or bronze bushes?
You mentioned that the Blockley’s look nice on an Ace, you wouldn’t happen to have an image that shows how it looks? Thanks in advance.
Kind regards
Jonas
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Jonas
Rock steady at 100 kph is better than the dreaded tracking. Needs a flat, smooth and dry road. Dare I ask whether at straight ahead you have slightest drag or a bit of free play and,if so, how much?
Michael
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Jonas
You refer to 'old X's'. As Barrie Bird put it to me 'if your tyres are 10+ years old any replacements will transform your car'.
Michael
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Michael,
There is the slightest drag at roughly a 100 kph, but I have to say that I'm rather pleased with how the car behaves now. I feel I can trust it a whole lot more now than before.
The type of tyre and condition / age of the tyre and condition of the road you drive on are definitely all very important factors in how the car behaves. I have driven 31 with:
Antique Michelin X's, Dunlop Racing, Excelsior Racing (Cross ply), Excelsior Radial and modern Michelin X's, all 5.50 x 16.
What I find intriguing is that straight line stability was possibly better with the 20 year old Michelin's than the new X’s, grip is something else though!
Jonas