AC Owners Club Forum
AC Owners Club Forum => Ace 'Brooklands' Forum => Topic started by: Adrian_S on June 05, 2015, 13:45:15
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Does anyone know what ball joint AC used on the Ace front lower hub to track control arm please? I had a spectacular failure in Brighton yesterday and the garage I was recovered to are scratching their heads. I was told by the former owner it was likely to be Granada Scorpio but this is not the case. If anyone can help, I would be extremely grateful!
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The lower ball joint as far as I know is a Ford Transit 1985 to 1991.
But, this has a tapered pin with a threaded section at the top for a nut.
I may be wrong but I seem to remember some had this fitted and some had hubs which had been machined for a parallel pin with a grove in, that then uses a pinch bolt through the lower part of the hub which is split so the nut and bolt pinches the pin.
Which has your got? I am almost sure that the ball joint is the same part number for both but one has been machined parallel and the length adjusted to fit.
Wally
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Part number 502 1430, Don't know what make (Maybe Ford part number) but google shows it.
Wally
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I had this problem last year. The ball joint is from a Ford Transit as you say. The spindle has to be machined down to fit, but check the diameter of the spindle first as there are two different sizes of pin that have been used depending on which car you have apparently.
Neil Fisher at Redline Engineering can help you with a new pair.
/Paho
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Thanks Guys I managed to obtain one from Neil Fisher whom confirmed the need for post machining. This accounts for the £160 unit price & just for info Neil only has one remaining in stock & not sounding keen to get another batch done. Thanks for all your help. I'll pick up a transit version as well and talk to my Cnc shop.
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I heard it was Transit joint with taper machined to provide parallel fitting. How on earth you can turn down the taper when the ball will simply spin in the socket is beyond me. But I've not studied one to see is and how it can be done.
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..... you do it carefully. Its not something I would tackle personally. But luckily the workshop I use used some lateral thinking.
I needed a ball joint temporarily so that we could move the car around in the workshop while awaiting new parts from UK. The workshop I use made a spare for me by holding the ball joint pin in a lathe by its threaded end and turning it at a slow speed. The pin does not move around much in its seating as the joint is quite stiff when new, those I've purchased are at least.
The tool used for cutting needs to be rated for hardended steel. The threaded end was cut off when the machining was finished. The slot for the locking pin was machined with an angle grinder.
BR /Paho
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Gentlemen one hesitates to interfere from a position of ignorance, but it is difficult to to feel entirely comfortable reading about ball joint tapers being reduced to parallel pins: Especially when it seems that failures are being encountered. I suppose thought has been given to leaving the ball joint as manufactured and putting a taper in its female partner instead ? If that is impossible perhaps the female part could be reamed out, still parallel, but made larger, while a tapered I.D. sleeve is fitted to the ball joint taper pin to give a parallel O.D. Finally if one must remove the ball joint taper it might be better to grind the pin and get some expert advice on what heat treatment is then required; not that I have a clue how to heat treat a pin with the ball assembly attached - cryogenic treatment ? Any real engineers out there ?
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B.P.Bird does have a point. Adrian, what was the nature of your "spectacular failure"? Was it failure of the ball joint stub/pin where it locates in the hub carrier?
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Hi Max The spectacular aspect was more to do with careering around a roundabout at speed with just one wheel steering etc. The joint sheared just above the ball and there was evidence of corrosion inside the shear indicating it was probably cracked for some time before finally letting go when I hit a pot hole on the roundabout. The consensus between my auto technicians & CNC shop was metal fatigue and/or metallurgical defect rather than design fault. The Transit component is plenty heavy duty and fit for purpose they think although you can't rule out stresses induced by post machining (either in process or by alteration) I was just looking to get back on the road but would be interested in any design improvements.This would take more time (and the Ace is my daily drive!) I'll endeavour to post some photos soon (just on a train at the moment) but please feel free to email me on adrian.short@btconnect.com and I'll send some high res images.
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Just to ensure I didn't give the impression that my ball joint had a catastrophic failure.
Both the UK MoT and the Swedish "bilbesiktning" results indicated that the ball joint had excessive play, but not enough to take the car off the road (the car had travelled 92K UK miles). So I changed it before the situation became "catastrophic".
I think you just had very bad luck Adrian.
I would not be happy with changing the present setup without knowing the ramifications.
BR /Paho
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I am almost sure a taper pin with a nut on top of the hub can not be used, it was along while since but I seem to remember that the abs reluctor ring and the bearing cap are in the way and the lower part of the hub casting just does not suit adaption.
Wally
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I am attempting to insert a photo of the fractured ball joint [http://shawlineassetmanagement.co.uk/PhotoAlbumsPro/Album_nr9w4l/img]
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OK that went well! I'll experiment some more!
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2nd time lucky? The link seems to work on preview - here we go...[http://shawlineassetmanagement.co.uk/PhotoAlbumsPro/Album_nr9w4l/Ball3.JPG?cache=0.6975180204026401/img] It's interesting to note Wally's comments on his reply to my Steering Rack post. We found no spacers installed on the rack fitted to my car, to inhibit the lock. Consequently, the wheels do rub on the suspension at full lock. Now, when reversing under full lock, the front wheels can 'scrub' across the ground exerting quite high forces on the ball joint. My garage and I are now thinking that this is where the damage may have been done. I am hoping to fabricate some kind of preventer stops to limit the lock (when I can find some time!) and meanwhile try to avoid using full lock! Footnote: just wanted to point out that my particular Ace is one of the last 'project' cars that was about 80% completed at the works, then privately finished and SVA tested.
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Like this!:
(http://shawlineassetmanagement.co.uk/PhotoAlbumsPro/Album_nr9w4l/Ball3.JPG?cache=0.6975180204026401)
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Originally posted by nikbj68
Like this!:
[img]
Sorry I don't have any specific information but, from memory, AC Cars (Labinsky era) introduced a modification to cure a problem similar to this.
I strongly recommend you investigate this further before taking metal off what is a highly stressed and safety critical component.
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quote:
I strongly recommend you investigate this further......
Further to my earlier post David Hescroff, a long standing ACOC Member who does not subscribe to the Forum, has agreed to the following being posted on this thread.
David had a similar failure on a late model Ace which, in his case, occured when reversing on lock.
AC Cars had already modified his early model Ace to prevent the problem, and supplied the parts free of charge to fix his later car.
David's recollection is that there was a recall at the time, his later car having slipped through the net.
David's advice is to contact Neil Fisher at Redline. Neil is understood to know of the problem and the correct solution.
I would add, from an engineer's standpoint, that all Brooklands Ace owners should have their cars checked as a matter of urgency.
As not every owner subscribes to the Forum, the Ace Registrar may also consider it prudent to inform owners in writing
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Many thanks ACOCArch this is wise advice. I have some more pictures to add this one being the stock Transit ball joint, pre machining
(http://shawlineassetmanagement.co.uk/PhotoAlbumsPro/Album_nruijk/small.DSCN3842.JPG?cache=0.32802592078223825?cache=0.9681336083449423)
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Here is a picture of the post machined article as supplied by Redline
(http://shawlineassetmanagement.co.uk/PhotoAlbumsPro/Album_nruino/small.DSCN3841.JPG?cache=0.0827350600156933?cache=0.4862628341652453)
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And here are some pictures of the fitment on the hub carrier. The proximity of the hole to the upright section won't allow a nyloc nut above, hence the need for a pinch bolt arrangement.
(http://shawlineassetmanagement.co.uk/PhotoAlbumsPro/Album_nruiwn/small.DSCN3845.JPG?cache=0.2762963641434908?cache=0.6090557225979865)
(http://shawlineassetmanagement.co.uk/PhotoAlbumsPro/Album_nruiz7/small.DSCN3859.JPG?cache=0.1523434561677277?cache=0.9500388228334486)
I spoke with Neil Fisher whom confirmed that my car has the recall fitment and that this design had been adequately SVA crash tested to be fit for purpose. However, he did concede that the steering geometry was such that, under full lock the wheel angle was very acute, and could exert undue force on the lower ball joint. I hit the pot hole quite hard and it's not unknown for other vehicles to suffer suspension damage in this way. However, I am looking into ways of restoring strength to the ball joint and would greatly value any suggestions.
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Very interesting info, I appreciate the effort to put it up on here. Has anyone managed to fit end-stops to reduce the lock on the steering?
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Has anyone managed to fit end-stops to reduce the lock on the steering?
Fitting rack end stops might reduce stresses at the extremes of lock, but not for potholes! Another possibility is that there is not sufficient articulation in the joint at the combined extremes of steering lock and full suspension travel.
The broken parts may have fatigued for a while, with the pothole the last straw. Examination of the broken part by a metallurgist would quickly determine the failure mode. A workshop check of articulation at the extremes would resolve that issue.
The AC 3000ME has end stops on the steering rack. These were a homogolated AC Cars Ltd design to modify the Triumph rack fitted to the car. The idea has stood the test of time (33 yrs on my car).
If rack end stops are the answer for the Ace, strictly speaking they should be approved for the car. The 3000ME stops would almost certainly not fit the Ace rack. However, if a competent engineer wishes to take up the idea I would be pleased to supply the AC Cars 3000ME drawing, on a strictly advisory understanding, as one basis for a design which might be suitable for the Ace.
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quote:
Originally posted by Nev
Very interesting info, I appreciate the effort to put it up on here. Has anyone managed to fit end-stops to reduce the lock on the steering?
Quote from the Rack Thread below
From what I remember we fitted a rack from a VOLVO 740 ID No. 34003798, the only thing we had to alter was putting spacers on either rack end (behind the rubber gaiters)to stop it turning as far when on full lock.
All we did was put a collar with the same outer diameter as the outer diameter of the knuckle joint, and with an inner diameter being a tight fit onto the rack, and then re-fit the knuckle joint. Obviuosly we did this on both sides. The thickness of the spacer then limits the lock as the spacer instead of the knucke joint comes up against the outer rack housing when on full lock. I can't remember just how thick these were but at a guess they would be around 25 to 30mm.
Wally
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Thanks Wally can you remember the material you used for the spacers, nylon perhaps or aluminium? I have the old Volvo 740 rack to experiment on. Your help really invaluable, thanks!
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We used mild steel but only because as we had a piece that was almost correct size, we just trimmed it slightly and cut it in two.
Wally
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I've discussed ball joint designs with some other Ace owners and discovered that earlier Brooklands Aces were fitted with a different modification to the transit stock ball joint. I've had some more ball joints machined to emulate this design shown here on the right
(http://shawlineassetmanagement.co.uk/PhotoAlbumsPro/Album_nruit9/DSC_0025.JPG?cache=0.26386270858347416?cache=0.8344390303827822)
This design continues to use a parallel machined shank but now features a scalloped slot along one side to accommodate the pinch bolt (rather than a groove machined around the whole circumference). Here are the two machined ball joints ready to fit
(http://shawlineassetmanagement.co.uk/PhotoAlbumsPro/Album_nruit9/DSC_0027.JPG?cache=0.09720890945754945?cache=0.18144701840355992)
This design leaves a lot more metal in place and should, theoretically, be much stronger. My CNC shop achieved a smooth finish and ensured all edges were radiussed, to avoid any stress cracks developing. According to another owner, in excess of 90k miles were achieved on this design. I'll have these fitted as soon as possible and look forward to reporting back! Now to machine some rack end stops to Wally's description.....
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Adrian - the slot instead of circular groove is far better idea, although the failure you experienced wasn’t at the groove, but lower down. I guess another solution would be to machine the hub carrier to same taper as ball joint (should be sufficient meat available not to weaken carrier), but retain pinch bolt as means of securing joint in place. Out of interest what was the cost of removing taper from transit ball joints?
As Wally says the stops are nothing more complex than spacers fitted behind the tie rod knuckle joints of sufficient thickness to restrict rack travel so on full lock tyres don’t rub against inner wing valance. You can use steel, aluminium, plastic - whatever comes to hand. The spacers can be fitted as washers (cheap and easy to make) by removing the knuckle joints or made in two halves with screws holding the halves together (lot more expensive!) if you don’t want to remove said joints.