Front upper wishbones - how tight?

[David-122i4]

Hi,

I've removed wishbones and dampers from an early '98 Elise and am attempting to fit new front upper wishbones. I took pictures (see below) of the shims that were in place, but given the amount of rust on them it's difficult to say what thicknesses they were. I've put the new upper wishbone in place and squeezed as many new shims as I can (3mm behind the front arm, 1mm in front), along with the snubber washer, and get a fraction of free play; the wishbone doesn't move left to right, but there's perhaps 1mm play where I can pull one side of the arm and push the other. When bolted up, the wishbone moves very easily up and down, where the rears were very clearly a much tighter fit (no shims on the rears) and the rubber bushes resisted easy movement up and down.

Do I need to spend more time wedging another shim in place to make the front uppers a really tight fit, or should there be a little play? I'm not convinced I can get any more shims in, but haven't resorted to violence yet

Thanks for any input,
David

[quarryman111]

The shims are there to adjust the geometry rather than just taking up slack. You’ll need to purchase a new set, fit approx as original and then get a full geo done.

[David-122i4]

Yup, understood, thanks - I've fitted new shims and understand about castor adjustment and the need for an alignment check, I'm just unsure how hard I need to try in order to wedge more shims in there. I have a selection of 1mm and 2mm shims and I can't add another 1mm with my bare hands. But that gives me the tiniest diagonal movement. Is that OK, or do I need to find a way of squeezing that extra 1mm in there to take out all slack?

Thanks for the reply!

[BertBert]

I don't know the answer for your lotus but from my layman's experience working on race cars, any movement you can feel just by hand feels like it needs attending to. That's probably what you are thinking, so but much help in afraid!
Bert

[David-122i4]

Thanks Bert, that is useful and confirms my worst fears

[quarryman111]

I would be inclined to ‘tap-in’ another shim if that’s the type of force needed.
Sorry to throw-in another variable but have you changed the bushes? The OE or similar rubber ones tend to be better dimensioned than some of the eg: poly replacements.
Also, only tighten the bolts with the wishbones in the running position to avoid building-in a preload.

[David-122i4]

Yes, new bushes in the new wishbones and I went with OE spec. I'll see if I can get that extra 1mm shim in there. I'll be jacking the uprights up a touch off the axle stands before tightening up - assuming I ever get there