I have suffered for years from excessive and very rapid wear on the inside of ONLY the front right tyre. As it’s only one side it cannot be toe-in error, but I suspect camber or caster on just that wheel, and am about to have that gauged. I believe the XJ40 had no adjustment for camber, but during the replacement of upper wishbone bushes I noted shims said to be for adjusting caster. I cannot find anywhere in my extensive collection of Jaguar XJ40 manuals, the actual method of placing those shims to correct caster one way or another (if that is the problem). Anyone found a credible reference?
See if this helps;
And this one
Thanks Robin, but unfortunately those don’t help. My shims are at the ball joint end of the wishbones and not the subframe. And I don’t have even a trace of steering pull. What I want to know is which side of the ball joint the shims should be swapped to for more +, or less -, to balance a workshop reading of caster negative - or positive + !
Take the car for a wheel alignment .
Thanks for your post! Most of us here do our own work on our Jags, and I prefer to do mine too, though detailed technical advice from other enthusiasts is always welcome. The local wheel alignment place is not equipped to do caster adjustments (only measuring and doing toe in (a trivial adjustment and the excess wear is only on one side)). The actual resiting of caster shims is something I can do in my own workshop. It’s just that, having not done caster shim resiting before I am naturally keen to know which was gives negative and which way positive, although I will have the final result checked at the local alignment shop (see my first post) as you suggest.
It certainly does Robin. That appears to show that positive caster means putting the shims to the front of the ball joint and vice versa. And if excess positive caster is shown we need more to the rear side of the ball joint. Many thanks!