Messages

16

Ace, Aceca & Greyhound Forum / Re: AC Ace steering box?

« on: November 18, 2022, 02:41:47 »

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

17

Ace, Aceca & Greyhound Forum / Re: Ac ace Bristol rear wheel bearing

« on: November 10, 2022, 22:37:03 »

Jonas

Might be worth talking to The Vintage Bearing Company. Their website looks promising.

Michael

18

Ace, Aceca & Greyhound Forum / Re: Ac Aceca Battery type?

« on: November 04, 2022, 01:22:01 »

Good morning gentlemen

I described above the battery tray in my 1959 Aceca. I did this from memory which turned out to be faulty. When I looked at it closely, or as closely as you can from above when it's full of battery, I found it is two angles with a steel plate spanning them so that it looks like a channel. I have decided that it is not an original AC tray. Sorry about that false start.

Nick has kindly posted pictures (too difficult for me) of a battery tray from a 1957 Aceca I used to own. Looks scruffy but it was in stock for 50+ years. I feel sure it is original AC. The steel is 14G (0.080" = 2.032mm). The key dimension is 252mm between inside faces of the lips on the vertical legs (maximum battery length), and the bolts are 1/4".If any of you would like to have further detail please let me know.

Barrie has alerted us to the fact that early cars had a different battery arrangement. Later cars had the 'transverse' mounting but AC may have fitted trays other than the 1957 one pictured above.

Michael

19

Ace, Aceca & Greyhound Forum / Re: AC Ace steering box?

« on: October 31, 2022, 01:06:48 »

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

20

Ace, Aceca & Greyhound Forum / Re: Ac Aceca Battery type?

« on: October 27, 2022, 01:25:59 »

Nick
Nice pictures, but not of an original AC battery carrier. The original was a folded symmetrical channel (haven't measured it but I guess 12g MS.) with two welded in tubes to take through bolts with threaded ends (5/16 BSF?) through holes in the the two chassis outriggers. The battery was constrained fore and aft by the channel and outriggers. It was constrained sideways by the two tubes and their bolts through the outriggers. Your pictures show only one tube, a welded on angle (very ugly welding - not AC) and a rectangular hole (not AC -what's that for?)
I shall try later to post pictures of an original AC battery carrier and give you key dimensions. These will provide info re the modern battery with the highest ampere hours (perhaps 60) which will fit in a proper AC battery carrier.
Michael

21

Ace, Aceca & Greyhound Forum / Re: AC Ace steering box?

« on: October 10, 2022, 03:19:14 »

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

22

Ace, Aceca & Greyhound Forum / Re: AC Ace steering box?

« on: October 10, 2022, 02:50:56 »

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

23

Ace, Aceca & Greyhound Forum / Re: AC Ace steering box?

« on: September 05, 2022, 01:15:34 »

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

24

Ace, Aceca & Greyhound Forum / Re: AC Ace steering box?

« on: August 23, 2022, 04:09:02 »

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

25

Ace, Aceca & Greyhound Forum / Re: AC Ace steering box?

« on: August 18, 2022, 02:43:11 »

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

26

Ace, Aceca & Greyhound Forum / Re: AC Ace steering box?

« on: August 03, 2022, 00:38:34 »

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

27

Ace, Aceca & Greyhound Forum / Re: Aceca Bristol tool kit and jack

« on: November 16, 2021, 00:37:46 »

The tools seem to have been answered outside the forum leaving 'what is the correct jack?'.

I am now on my third Aceca Bristol. AC changed details between cars and over time so there may not be a single 'correct jack'. My first Aceca came with a Lake and Elliot S414 (15 cwt) jack and a 30'' long square shaft with a square end which clicked into the jack and an eye at other end for a wooden handle. Can't remember if and where that was stowed. My second Aceca came with nothing and went the same. My current Aceca came with no jack but two 22'' square shafts which lock together, have the same square which clicks into an S414 (and perhaps others) anjd a hole at the other end for a round bar as a handle. The two shafts are attached to the inside of the RH vertical face of the spare wheel cover and the bar, plus a copper/hide, is stowed on the rear vertical panel behind the spare wheel and under the cover. I mention these details because I haven't seen any jacks for sale with an operating shaft.

I recently bought a Lake and Elliot S414. The lifting head is a shallow U with a concave base and the minimum overall height is 5 1/4''. A Shelley 7DL has been suggested but its minimum height is quoted on a website as 6 1/2''. I believe AC stowed the jack standing in the 'triangle' at the front LH of the spare wheel (where else could it go?). The internal height of my spare wheel cover is 6'' as is the 'height' of the 550x16 Michelin X on the spare wheel. So the cover sits on the tyre clear of the S414 but would not do so with a Shelley 7DL. Also if had the dreaded puncture in my 'low slung' Aceca I would rather fiddle in 5 1/4'' than 6 1/2''. Remember it's cold and it's raining!. Where you jack it up is another question. I can find no clue re jacks in Rinsey Mills' Original Ace and Aceca other than a picture of a jack in the boot of an Ace. This is not an S414 but may not be original. Perhaps my 30'' shaft was from an Ace.

So I think it is very likely that AC supplied the S414 for Acecas. They may have supplied others but I recommend the Lake and Elliot S414. I think the case for the S414 is, as lawers put it, persuasive if not conclusive.

Michael

28

Ace, Aceca & Greyhound Forum / Re: Aceca seats

« on: November 05, 2021, 16:34:44 »

Just seen a pair of Aceca seats for sale on ebay.

Michael

29

Ace, Aceca & Greyhound Forum / Aceca windshield (USA)

« on: October 22, 2013, 15:07:07 »

Suggest you try Pilkington Classics at Urbancrest, Ohio - telephone 1.800.848.1351.  Pilkington made the original glass under the trade name Triplex and Pilkington Automotive still make windscreens in the UK. I think the price would be OK, delivery time dependent on filling a container for sea freight so could be slow.

30

428 Frua Forum / AC Frua Restoration Part 2

« on: December 04, 2011, 23:26:44 »

Emmanuel
   Re boot - CF6 rear panel is body colour down to the joint with the boot floor and black forward from there - looks right.
   It sounds like all convertible boot interiors were much the same. Two carpeted plywood panels over the spare wheel and battery compartments and an open trough round the rear and sides. Always seemed to me the least attractive or practical part of the car and I had no hesitation in modifying mine. As its not external I suggest you forget about originality.
   Michael