lvrpool32

I'm in the process of putting my offset trailing arms onto my car and I have a question about the shims.

I have 2 '69 vettes in the garage right now, the shims on mine have the trailing arm basically centered (ie equal amount of shims inboard and outboard) where as on the other car there are more shims on the outboard side.

This brings me to a couple of questions...
1)does putting more shims on one side or the other on the trailing arm move the wheel further in or out in the wheel arch?

2)how does the suspension make up for the bigger distance from the trailing arm spindle to the diff? I know its only 1/4" - 3/8" depending on the shims ..but do the diff yokes slide in and out? Or is it just the suspension has less up and down travel?

cheers,
Nick

mandm1200

I wondered about that myself. I then told myself that the shims in the front of the trailing would not affect the wheel in regards to it's placement within the wheel well. The half shaft would have to be lengthened or shortened to move the wheel.
I am curious as to what the trailing arms shims do. In looking at the suspenion, I assume they are there to set the toe. Looking to hear from the experts!!

Gordonm

The diff yokes should not slide in and out. The shims set the toe of the rear wheels.

jpatrick636

mandm, I wouldn't call myself an expert but; you are correct. The only thing the shims do is adjust the toe. Try to get the hub as strait as possible and get the car to an alignment shop as soon as it's drivable.

ivrpool, The trailing arm itself sets the location of the suspention from front to back. The half shafts set the location side to side. The shims rotate the wheel on the horizontal axis of the u-joint closest to the wheel. (Toe) The strut rods rotate the wheel on the vertical axis of the same u-joint. (Camber)

OldSchool

The shims set the toe..I put mine in evenly spaced (equal number) on each side.. when I went in for the alignment, the tech moved them around as prescribed by the machine..

Z-man

That's right. Basically, Vettes need to have all 4 wheels aligned to a certain degree unlike most cars that only need the fronts aligned.