any of you knowledgeable guys interpret this for me pls, plus or minus front l.h. side shims? I am not bothered about the back as I removed the shims to allow clearance for fat tyres, but the bottom centre on the pic, 0.03 deg. to the right, what could cause that?

 

The two main causes of thrust angle variance are rear toe and rear cradle alignment. Since the XJS does not have a rear toe adjustment, it is most likely caused by the rear axle not being perpendicular to the car centerline and parallel with the front axle. Pretty common to be slightly out because of the way the rear cage is located, don't think 0.03 is something to worry about.

Obviously this assumes that there are no bent or failed components in the rear end.

Cheers,

Allan

 

I would even up the front camber. If you are an enthusiastic driver go -1deg. If you set the front toe to 0 it will improve turn in significantly with a slight decrease in straight line tracking, I have done this on all my daily drivers for years.

 

Yep, I agree with Warrjon, even up the camber in front. As it stands now you will experience something called camber thrust as the two wheels are not pushing against each other with even force.

Cheers,

Allan

 

Like AllanG said, this is the Trust Angle and is almost dead nuts on. Even from Coventry they are out of spec more than that. There is much more human variation with a hand-built car than computer controlled assembly lines.

Even straight axle cars have more variation.

 

thanks guys
the only front top shims available from jaguar are + 0.031" thick, is there any maths that I can use to calculate the required thickness to move the l.h. side from -1.05 deg to -0.49 deg, or even both sides to +0.025 degrees

 

As I recall, a 0.062" shim makes about a 0.25 deg change in camber.

Adding shims will make the value more positive, removing shims more negative.

Cheers,

Allan

 

Hate to get off topic, but where do you get camber shims? Are they a universal part of a Jaguar-only thing?

 

They have them here Wishbone-Front-Upper - Parts For XJS from (V)179737 to (V)226645 | Jaguar Classic Parts UK

Cheers,

Allan

 

Adding shims will make the camber more negative not positive

 

Oops, you are quite right. I muddled myself up thinking about the rear camber

Cheers,

Allan