[rsj]

Have just installed all new front suspension in my 69 Spider (ball joints, tie rods, adjustable upper control arms) and am not sure whether to torque down the large bolts that locate the upper arms in the engine compartment, as I have yet to install the engine/trans.
Of course, tool access now is optimal, but the position of the arms will shift significantly when the weight of the drivetrain is added to the front end (but also, much less access to the bolts)
Not sure what to do. Suggestions?

 

[darth dino]

if you're running a rubber bushing in that upper arm, then yes, it needs to be at ride height when you tighten the mounting bolt.

if you know where the ride height will be, i would think that you can jack up the suspension to the correct height before you install the spring. tighten the mounting bolts, then install the springs and then the drivetrain. this won't be 100% accurate, but should get you pretty close. ideally, you should reset them once the drivetrain is in, and the exact ride height is obtained (which negates the whole idea of pre-tightening ). if you really want it just right, then you would also ballast the seats to their most common load before tightening the mounting bolts.

the lower a-arm mounting bolts do not have this problem, because they are spherical bearings and will not have a static position like the rubber bushings do. if you are planning any performance use for the car, like autocross or track days, it is a neat trick to use a lower a-arm bearing in the upper arm for more precise control than the rubber bushing - but it carries a penalty of a slightly harsher ride.

 

[rsj]

Thanks Dion! I think I'll just wait to tighten, as you mention, with drivetrain installed and person in driver's seat for optimal ride height (it will just be a little more hassle).

 

[Andrew]

I've always been able to get a wrench in both sides, even with the engine installed. I would definitely not do final tightening til all the normal weight is on the front end.

Andrew