X-100 XKR front suspension top wishbone locked-up

JustLovingIt · August 31, 2023

Gday all

I am in the last stages of rebuilding the front suspension, using all new rubber bushes, (not PolyBush etc), and new ball joints.

I very carefully assembled the new 'slipflex' bushes to the top wishbones. I fitted the yellow thrust washers first which fits over the sliding centre sleeve, then the plain washers that don't fit over the sleeve. Then the chromed washers, with the domes facing away from the rubber bush. Then the two shims, as per the Jaguar WS manual, Front Caster Adjustment. (UK so Pack 1 is 1 thick shim, Pack 2 is 1 thick, 2 thin, Pack 3 is 1 thick and 1 thin, Pack 4 is 1 thick 1 thin.)

I did exactly the same for the other bush, but in reverse obviously and then exactly the same for the opposite side and torqued the fulcrum bolt/nut up to nearly 100Nm. The result was the whole wishbone locked-up and I was able to jack-up the car without the suspension even moving. When I slackened-off the fulcrum nut, the suspension was OK, so I know it's not the lower control arm bushes.

Does anyone know what's going on, whether the Jaguar manual torque figure of 98-132 Nm is correct and how I can somehow get it right without having to remove the whole crossmember again?

PS: I am an Engineer and I can easily see the inner circumference of the flat washer is crushed in way of the inner circumference, which would lock the washer and possibly the sleeve to the fulcrum bolt. I can also see the same thing happened on the old bush sleeves. This seems OK as long as the axial compression exerted by the fulcrum bolt tightening doesn't compress the bush via the thrust faces. But I think it is. and that's seems to be the problem. Thanks in advance for any suggestions!

JustLovingIt · August 31, 2023

Actually. I hand my head in shame! I had the chrome washers round the wrong way. Silly mistake but I followed how I dismantled it.

I still don't know how the torque recommended in the w/s manual, <100 Nm, does not cause deformation of the washers. But I accept the errors which I inherited from previous owners and, (my excuse, lack of a proper w/s manual drawing!)