[murphwiz]

Having trouble with my 9-5, the rear tyres are scrubbing badly on the inner edges... now causing a nasty din from the back...
The camber appears to be 1.5 degrees to negative..

Is there a formula I can use to decide how much shimming is required to set the camber correctly..?

 

[mark e]

Yes, ish, but it may be a bit hit and miss depending on the exact geometry of thew suspension.

If we assume a very simplistic view in the vertical plane that what we have is a right angled triangle, then what you're saying is that the smallest angle in that triangle is 1.5 degrees. You need to measure the vertical height of the point you intend to shim from the horizontal axis about the supsension will turn to vary the camber.

Having done that, then your required size of shim will be tan(1.5 deg) = 0.0262 multiplied by the vertical height referred to above. e.g. if your vertical shim point is 80mm above the horizontal axis then you need to use a shim of 80*0.0262= 2.1mm

Isn't trigonometry wonderful stuff when someone else thinks about it eh?

 

[saabman]

Right to get a near perfect shim size you would have to do some simple drawing.If you draw a line 8.5 inches high (half of the 17" wheel) and then from the top of that line measure back 1.5mm or whatever the negative toe is! and draw a line back to the starting point of the first line making a "V" shape.Then you would have to measure your rear hub from the centre to the height of the top mounting bolts.mark this measurement on the vertical line and then measure the difference between the two lines horizontally.This would give a no doubt within tollerance shim size.you could knock a small (very small) amount off for the wedge efect the shim would cause,but this is how we used to work it out before the computerised 4 wheel alignment.

I will check on the machine at work if I get a chance Leon but this will give you a excellent head start
Edit to correct bad spelling

 

[saabman]

It took me so long typing that Bubbles beat me to it

 

[saabman]

In my original post I was not clear about the distance to measure back 1 degree=10mm so for 1.5mm negative toe you would have to measure back 15mm.

 

[saabman]

Plus those figures would give you a Zero camber mesurement.you would also have to adjust these depending on what the factory spec was.

 

[billj]

Leon, do you know what has caused this problem?

 

[murphwiz]

Originally posted by BillJ:
[qb]Leon, do you know what has caused this problem? [/qb][/b]

Well i've been told that its due to lowering...
but i'm getting conflicting info...
Apparently the 9-5's rear is ride height sensitive, i can see the theory of it working... anyway whatevers caused it, I need to fix it, cos its not good!!

abbott tell me eibachs are far too low and I should buy thier springs... shame mines the same ride height as thier very own 9-5 then eh??

So I'm off to trent sab on tuesday as they seem confident of fixing it with minimum hassle...