Upper wishbone ball joint

[andrewh]

I am just have a retighten of all the various suspension fittings on the new restoration and have identified a slight "knock" or play in both brand new top mounts. These were fitted and shimmed when I assembled the suspension, but now with the leverage afforded by the wheel I have some slight play. This is the across the car plane, not the up down or fore and aft plane. So if you waggle the upright you can see discernible play of the ball joint in relation to the upright itself. I tried cracking the nut tighter on the taper and this improved it but its still there. Whether it is play of the taper in the upright, ( its both sides of the car ) or the ball joint in the wishbone I cannot tell. Any of your suspension experts like to offer a opinion please? As I understand it the shims provide for up and down play, but not lateral as such. I suspect it may be some wear in the upper wishbone housing. If that is it I assume there is no fix other than to find a new wishbone?

[abowie]

If that is it I assume there is no fix other than to find a new wishbone?

Correct. The usuals sell an "upgraded" upper wishbone fitted with a modern plastic socket. I have used these on a couple of cars, with good effect. Can't speak to their longevity though.

[mgcjag]

Hi Andrew.....did you fit the ball joints as per the manual.....assemble with shims till ball is tight then remove 0.1m of shims.....the shimming dosnt just stop up/down movement becaus you are shimming the cup that sits on the ball..worth dismantling to check.... Steve

[andrewh]

Thanks chaps. It's a while since I did the upper joint but I would have read and re read the book for obvious reasons. If you are shimming the cup are you not shimming up and down movement ?

[mgcjag]

Hi Andrew....as you know the ball/pin drops in from above so it sits in a hollow, then the cup sits on top of the ball, so its sort of all round movement your shimming......if the shims were very loose you would have a sloppy ball up,down,front,back,side,side, you may just have removed a shim that was thicker than the 0.1m

[andrewh]

excellent . I will check how it is set up. I assume I can do this without removing the taper, which now appears to be well and truly locked in position. Smacking two mallets either side of the upright is not something I want to be doing on a brand new rebuild! I appreciate, it makes it harder to detect the correct shimming for the ball joint play though .

[mgcjag]

You will need to break the joint to check properly....Get yourself a ball joint breaker.....i have this one, works great https://www.machinemart.co.uk/p/laser-3 ... DQods8kAfg leave the nut on loose when you split it so you dont damage the end of the thread or have it fly out

[andrewh]

thanks Steve. I have about 4 different ones of these but they are all a bit too big. I will have another play rather than buy a fifth! thanks for the help.

[andrewh]

yes, reshimmed it and its gone now. Must have been a bit lose when built off the car. Its the advantage of having the leverage from the wheel that showed it up. Anyway, do you think that a looseness here would contribute to wheel wobble ? I guess the answer has to be yes, but interested in views?

[Peter27]

Hi Andrew. I had exactly the same issue with the offside joint. Re-shimmed and slight 'tremor' from front has disappeared, so I assume the problem does give a degree of wheel wobble.

[andrewh]

interesting that you had a shimmy on the front. Bound to have some effect. I feel sure. thanks

[Gfhug]

Andrew, can you remember how many shims you ended up using?
I'm using a spare set of upper wishbones (cleaned, zinc plated etc.) to minimise the time the car is off the road. I've tried with the 4 shims that come with the ball joint kit and they are still quite loose.

Thanks

Geoff

[andrewh]

about 6/7 shims from memory. Slightly frustrated that the spring in the kit will not fit through the shoes in the kits which means that you have a hard job getting the cap on. Anyway, about 7 from memory, and its removed the slight play.

[mgcjag]

Dont forget to measure the shims....fit as many as poss till the ball it tight then remove 0.1m as per the manual.....a narrow socket on the top and a G clamp helps you compress it, adding shims till tight...slide the circlip over the socket befor you clamp it......

[andrewh]

Forget the G cramp Steve! So yesterday. I find my side valve spring compressor is perfect

[mgcjag]

Nice to hear you have some good tools just thought i would add it in...im sure some struggle and just try to squeez it in with there thumbs.....ask me how i know

[Gfhug]

Thanks Andrew and Steve, it looks like 7 or 8 will be needed, so not much difference from your experience.

Cheers
Geoff

[rfs1957]

Since these sorts of parts can generate a rather fluid "market", would someone be so kind as to update the current state of play on these, please ? I've posted what my research threw up so far ............



I haven't stripped mine yet so not clear what I'm going to be faced with, but would like to understand the issues and what's on offer.

Re-con ones can presumably be required because the ball is running on a lower seat that is machined directly into the wishbone, which then wears to the extent that shimming can no longer compensate for the loss of metal ?

How much wear is "worn", and how many shims are acceptable ?

Is there much choice on suppliers / approaches for these re-con upper arms, and do they re-create the lower seats or just clean them up and use fatter shims ?

I think I understood from trawling with the search function that CMC do an alternative nylon "upgrade" for £120 + VAT a pop :

https://www.classic-motor-cars.co.uk/cl ... rated_3931

- unfortunately presented with the customary zero technical explanation or details of what fitting entails, tho' on JagLovers

https://forums.jag-lovers.com/t/upper-w ... /356890/19

it appears that you buy the kit then machine at your cost the wishbones to their spec ............

Once the existing ball joint is removed, the socket will need to be machined out to our CMC spec. Once that has been done we would shot blast and then send the wishbone away for plating ready for the new ball joint to be fitted. However, it is sometimes easier and cheaper to just get a new wishbone with the ball joint upgrade already fitted.

They also offer new wishbones at £270 plus VAT each, presumably with these same joints fitted ?

https://www.classic-motor-cars.co.uk/cl ... bones_4035

Has anyone put serious miles on these - I heard reports of annoying sqeaks from someone in the trade.

This is the current SNGB offer :



Have any members had success in freshening-up ball/socket with these parts ?

Many thanks.

[angelw]

Hello Rory,
I've had so little success with the Off The Shelf items, we make our own Balls and Cups. The problem seems to be more with the cup and invariable, the top surface of the cup needs to be surface ground to allow the cover plate and circlip to be assembled even without any shims. I don't understand why the after market manufacturers can't get it consistently right. It's not like they're designing something new, but just copying what already exists.

With regards to the lower socket that is part of the wishbone, if you can see, or feel appreciable wear, then no amount of shimming is going to rectify this. In the past, we have built up that area with the same material as the parent and then re-machined the profile using CNC machine tools. In recent time, I've machined the ball socket area to take a sealed ball joint from an MG-F. This requires the Socket to be removed completely and an internal thread cut to take the sealed ball joint assembly.

Regards,

Bill

[MarkRado]

You will need to break the joint to check properly....Get yourself a ball joint breaker.....i have this one, works great https://www.machinemart.co.uk/p/laser-3 ... DQods8kAfg leave the nut on loose when you split it so you dont damage the end of the thread or have it fly out

Hi Steve,
can you help me with the diameter (inner width of the fork) of that tool? Would be of great help to get the right one also from other suppliers,
thank you