I just changed out the front lower control arm bushing & shock bushings on one side of my XJR, planning to do the other side as well but my question is...
the workshop manual states the final torque/tightening of the lower arm nuts must be perfumed with the wheels on the ground? how is that even possible?

 

Most suspension work requires this so that you don't preload the bushings with the suspension hanging in mid-air. If you can get final torque them by crawling under the front, or get the front tires up on ramps with the weight of the car on the tires it would be best. 2nd option is to jack up under the control arm (carefully) to get some of the car's weight on that side, then torque.

 

Thanks M Hamilton,

I never use ramps so I wasn't even thinking about that! Sounds like the ramps will be the best option to do it properly. I already did the final torque with the car in the air then set it down on ground forgetting about the step that states to tighten to spec. with wheels on the ground....

I imagine it would be wise for me to get the car jacked up, loosen both control arm nuts and tighten a certain amount, then roll the car on ramps and finally torque to spec? Does that procedure sound right?
Before setting it on the ground, should I tighten to 1/2 of the recommended 129 ft/lbs?

What kind of problems would result from preloading the bushings? like I probably did by torquing to spec with car in air

 

It would be just as effective to get the car up on ramps, loosen, bounce, tighten.

 

I think they mean that you use a four-post hoist where the car is resting on it's wheels, and elevated so you can get access underneath to torque the bolts...

 

yes, 4 post is the easiest

having done it for years without a lift on lowered miatas, another trick is to use a 2nd jack on the suspension and compress it that way...of course with a jag don't start lifting on any aluminum parts.


basically you don't want to tighten the bushings down when they are in extension, picture the bushing twisting when you then put all the weight of the vehicle on them.

 

thanks a lot guys! Hopefully I didn't mess up my bushings by tightening and driving about a mile before realized I didn't follow procedure correctly

Many mahalos

 

what do you mean by bounce? once the nuts are loose press up and down on the bumper?

 

Ask the alignment shop to do it since you should be getting an alignment anyways after replacing suspension components.

 

pretty much