The rear camber is out on my car and I’d like to try and get it back in spec. I know the process is to change the size of the spacer shims on the inner side of the driveshafts. But the question is what sizes do I need?

I haven’t been able to find any references in Jaguar documents on how to calculate what spacers are needed.

I’ve made some crude measurements and using my fading memory of O level trigonometry I’ve calculated that a 1mm change in width of the spacer would equate to 0.5 degree change in Camber.



However, I’d appreciate if anyone has seen any reference material, or actually tried adjustment of camber and has any data. The spacers are too expensive (around £50 each) to go with a trial and error approach (the work involved in changing them and retesting isn’t a 10 minute job either).

I currently have a 7mm spacer on one side and 5.5mm spacer on the other. If I can't find relevant data my back-up plan is to swap the spacers and try and get before and after measurements to see if it confirms my calculations.


Thanks in advance

 

Have this in my notes(Jag dealership tested): 1 mm change in spacer thickness results in 0.37 degree change of camber and 0.11 degrees in change of toe.

Good luck!

 

I went down this path some years ago, and like you Brendan, could find no guidance on the impact on camber of a given shim size change. From memory, while the shims were not inexpensive, at that time their cost did not preclude buying a few for a trial and error, iterative approach, despite the pain that process would involve. Armed with a few likely shim sizes, I approached my friendly dealer, who in the course of looking up the parts casually intimated that they had never, ever, never never actually supplied or used any of them. Uncharacteristically, I paused for thought and went home to think again. I could tell my diff had been off at some point, and I noticed that the side where I wanted to reduce the shim size had a thick shim on it, and the other side the reverse....... You can guess the next bit, but to cut a long story short, the camber is bang on spec with the shims reversed. I suspect whoever had the diff off thought they were washers rather than shims.
This may be of no relevance to your situation, but thought I would pass it on anyway.

 

Thanks both for your input.

@katar83 So changing the shim resulted in change of toe. Not sure I can get my head around that but I will bear that in mind and check that also after the camber is done.

@countyjag I think ultimately your story may be relevant. With my calculations (and Katar83 numbers would work also) if I swap my right shim to the left that should bring it in spec. But I will need a smaller shim for the right than the other one that I have (Both sides have excess positive camber).
I have had all of the back end apart when I rebuilt the car so may have mixed them up. Also, back when I first got the car many years ago I had to install a rear wheel bearing and ended up having to replace the driveshaft with a used item. The nut had been cross-threaded (by the same mechanic who had also packed the wheel bearing with Copper Grease!). It's more than likely I just swapped the driveshaft with whatever I bought, without any knowledge of what the spacer was.


I'll update this thread when I get it sorted. Thanks again.