Upper wishbone ball joint shim - C24523

Does anyone out there have one of the original, factory 0.004" upper ball joint shims that are mentioned in several of the service manuals? I am interested to know what the internal diameter of the factory shims were, and whether they were originally designed to pass over the internal spring, or sit on top of it.

After disassembling one of my upper ball joints, I’m finding the same situation as @mldwyer described in the quote below (from this post: Upper ball joint rebuild), and his rationale makes sense to me. With the differences in height/thickness of the socket cup and joint cap installed in my car, compared to those in the aftermarket rebuild kit I just received, I’m questioning things. And, I’m curious to understand the factory design to inform me as I try and piece something together that’ll work properly.


Would’nt an assembled upper joint, brand new, be much better in
the long run?

I would think so, but I think the only way to purchase a brand new, assembled, upper joint is to purchase a new wishbone that goes with it ($$$).

That leaves me with using an upper ball joint rebuilt kit ($$). All new parts, but the socket is shorter, the cap is shorter, and the shims are thicker. I may be able use more shims to make up the difference, and that leads me to the question I’m ultimately trying to answer - were the factory shims designed to fit around the spring, or on top of it?

Rob Y

Hello Rob,
What do you mean by the socket; the cup into which the ball Pin fits? And the cap; are you referring top the Top Plate being thinner?

Of late, the numb nuts that make these kits appeared to apply such poor size controls, on parts that are easily recognized as being CNC Turning Centre machined, that most won’t actually assemble even when all shims are omitted. So maybe its a case that the penny finally dropped and they realized that for the kits to be used, its a requirement that they must be capable of being assembled.

With regards to your question relating to the shims, the factory originals sat on top of the spring.

Often, when there is a need to replace the Top Wishbone Ball Joint Assembly, the Ball Socket, which is a machined feature of the Wishbone, is worn. In this case, I machine the internal feature of the Wishbone to accept the Nylon Insert and Ball Pin unit shown following:

The following picture shows the finished machining of the Wishbone:

and the following picture, the finished article. This particular Wishbone is from an early S1 car that had A & A markings on the Top Plate. Accordingly, the job included a new Top Plate correctly marked.

Securing the Gaiter Clip as shown in the following picture is a worthwhile exercise:




That would be a good job for somebody in a machine shop who would

have a cnc milling machine to make these parts from scratch.

Rob, with your name are you a native from Poland, I lived in poland
for a few years during the war.

Walter Schuster

Yes Bill, I mean the cup that the ball fits in, and the top plate. Stacking the top plate on the cup and measuring, the new parts are 0.023" shorter than what was previously installed. Just to make up that difference will take two of the four shims that were provided (all four are ~0.0125" thick).

Today I was able to get all four shims and the snap ring installed (without the spring), and the joint was pretty tight but I was able to move it by hand. Tomorrow I’ll lube everything up, install the spring, and hopefully I’ll be happy with the final assembly.

Thank you for this information!! At least I can rest assured that won’t be a problem here!

I saw your approach on machining the wishbones in my search of the archives, and I appreciate you sharing it here again! This first one looked to be in good shape, and hopefully the other one will be too. If not, do you offer this as a service, or do you only perform this for the restoration projects you’re working on? I appreciate the advice on wiring the gaiter clip too - although that makes total sense, I’m not sure I would have thought to do that!

Rob Y

Nope - I was born in the US and lived here all my life. Different sources have indicated my name is Slavic in origin, which would include Poland, so I could have some distant relatives there. I’m not sure I’ll ever know though. I was told my name was “created” when my ancestors immigrated to the US, and the government/immigration folks heard whatever name was vocalized, and wrote “Yaskovic”. I have no idea if that’s true, but doesn’t sound too far-fetched. :thinking:

Rob Y

Hello Rob,
There should be 0.004" clearance in the ball joint when the spring is installed. The correct method of adjustment is to lightly grease the Ball Pin and Socket, assemble the components of the Ball Joint but omitting the spring. Use shims to obtain a tight fit of the Ball Pin in the Socket with the Top Plate and Snap Ring in place. Remove 0.004" of shim from the assembly and recheck. You should be aiming for the Ball Pin to move readily through it’s full range with pressure. Reassemble with the spring included.

I do offer machining and fitting the Nylon Insert Ball Joint System as a service. The AUD/USD exchange rate makes it viable to have the work done in Australia.



Thanks Bill. I appreciate the clarification on the spring to shim relationship. I’m just beginning to reassemble my FHC after a long break. I fussed with the ball joint assembly for quite some time back then. I had a 50/50 chance of getting it right. Aware of anyone who might have the inner and outer diameter of the original factory shims? Looks like a wonderful job with your modification.

I’m not sure Bill (@angelw) is on the forum much anymore due to computer challenges, but maybe Brent (@BrentKeats) knows the answers to your questions…