Suspension shims

I am rebuilding front and rear suspension taken apart by someone else. Most of the guidance talks about using the same shims when disassembled, as I do not have this info is there a stock start point for the various shims (not the brake ones as I realise they can be set by measurement) many thanks.

You can only set the suspension properly by measurements, James - camber and castor…

First you need the shims, and the number of shims, and their placing ex factory may vary. For the caster; you need enough shims to fill the gap between the upper wishbone arms and the upper balljoint. The castor is then adjusted by moving the shims between the front and the rear of the balljoint - the number of shims are ‘constant’.

You can start with equal number of shims for and aft on the ball joint, and no shims for castor - and take it from there…?

xj6 85 Sov Europe (UK/NZ)

Four per side I believe, the arms allow for some movement but I believe it’s always four. So two left two right as a starting point?

It’s sort of guesswork if the factory (sometimes?) fitted all shims of equal sizes, Daved - or used a mix of thicknesses for more precise settings…? :slight_smile:

xj6 85 Sov Europe (UK/NZ)

I don’t know, but those at the upper ball joint sure look the same?

Thanks all any thoughts on the shims where the half shafts join the brake discs?

Only prayers I think. Put it together without springs and bring them into mid laden position with the tool or a copy of it. Measure and go back in. I don’t know if there’s any better way. Probably not.

No other way indeed.
You could do it on the bench but it must definitely be verified/adjusted with the IRS in the car.

Are we talking about the IRS with inboard brakes? If so, remember that the shims inboard of the brake rotors are to center the brake rotors within the calipers. That can easily be done during initial assembly. If the camber of the rear wheels is already established, centering the rotors within the calipers is accomplished by moving shims from inboard of the brake rotors to outboard or vice versa. If you’re going in assembly order, though, you put shims on the inboard side to center the rotors, then assemble the whole car and check the camber and adjust the shims outboard of the rotors to correct. It is significantly easier to get to the shims outboard of the rotors than to the ones on the inboard side.

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Got it! Center the rotors and then add/remove shims on the outside. Which is comparatively easy.

By a magnitude of many thousands!
I would even say to the limit of impossible with the IRS in the car.