Hi,

I believe I’m going to need to replace either the upper or the lower control arms for my 2004 LS430. I’m hearing clunk clunk sounds. Been reading a ton of threads on the forms to raise the car up and shake the tire at 9-3oclock and 12-6 o’clock. How do I know which control arms are bad by doing that?

also, from the readings, I’ve seen many say to not tighten any bolts, and to just make them snug, then load the weight onto the arms, then torque it so that it doesn’t add extra weight/pressure to the arms. How do I preload the weight to the arms before torquing them? Do I put the tire on and put the car down, then tighten to bolts? Or what’s the best way to do it, if I’m replacing the entire arm (no idea how to remove brushing so I’ll prob replace the entire arm).

 

Play at 9 and 3 would indicate play in the steering(inner or outer tie rod ends. At 12 and 6 would indicate play in the upper or lower ball joints. At any other point besides those could indicate play in the wheel bearing, you can spin the front wheel independently and listen for growling, humming or roaring sounds coming from the wheel bearing. To check play at bushings I use a pry bar and try to move the bushing, if there is any movement replacement is needed. I usually check with the suspension unloaded(full extended, jack stands on the frame rail or pinch weld) or loaded, jack or jack stand on the lower control arm to simulate the weight of the car on the suspension. That is also when to torque the bolts, just place a jack on jack stand on the control arms as far out as possible to load the suspension. You want the lower control arm to be parallel with the ground, not fully extended.

Common bushings to go bad on the front end of these car is the rear lower control arm bushings(replaceable separately from the control arm) and the upper control arm bushings which the whole control arm is fairly cheap aftermarket. I used Beck Arnley with no issues from Rock Auto.