Subframe bushing bolts '90 100
Dave C
conner at cfm.Ohio-State.edu
Thu Mar 21 22:43:35 EST 2002
Richard,
I understand someone recently worked on the front suspension, replaced
control arms (C/A), and now the car rattles...
What other work was done? New subframe bushings? Would they have had any
reason to drop the subframe? Control arm replacement does not involve
dropping subframe, but r&r of subframe bushings does.
Subframe should not move like you describe. My guess re: the spinning bolt
is that it's stripped. The nut for that bolt is a captive nut (not tack
welded) inside the body of the car with, I think, a small access hole in
the body. You probably cannot remove/replace the stripped nut. What could
be done is to drill out the stripped nut and place another nut on top of
it. The bolt is long enough to reach the second nut. But ... the subframe
may need to be dropped to drill out the old nut, and the bolt is probably
also stripped so you'll need a new one.
Ball joint bolts should be inserted from the rear... this is as per Bentley
and on the F/A or parts fiche... the reason is to keep the bolt from
sliding out in case the nut would fall off ... braking force is much
stronger than acceleration.
Why would one ball joint shaft protrude farther than the other? Don't know
... My only guess is a bolt that is worn or wrong size. These bolts should
be renewed as per Bentley, but I believe they are often re-used. It would
seem to me the risk of a broken bolt would be much greater than risk of the
nut coming loose and falling off.
Re: the rattle ... The loose sub-frame sounds like a definite possibility.
But there could be other problems. I'm not sure how important it is to
tighten the ball joint bolt with the cars weight on the suspension, but the
sway bar link to the control arm must be tightened this way or it will
trash the C/A bushings. These nuts would certainly have been removed
during C/A replacement. Replacement of the C/A bushings would be standard
practice.
---------------------
Dave C.
While trying to track down an annoying suspension rattle I noticed that my
subframe has fairly easy movement in it when levered with a pry bar. I put a
socket on the right forward bushing bolt to attempt to tighten it (as it was
loose enough to spin the washer with my fingers) and it just spins as if
stripped. Two questions: 1. How much movement is normal in the subframe?
2. What is the subframe bushing bolt threaded into? Did a tack welded nut
inside the frame break loose or are the threads in the frame itself and
simply need to be tapped out?
On another subject. The lower control arm ball joints have the bolts going
from front to rear with the nut on the rear side. Is this correct? I always
thought that the bolt should face forward with the nut on the front side. I
also noticed that the ball joint shaft is protruding further out the top of
the strut assembly on one side than the other as if one side is sitting lower
on the ball joint than the other. (like did the guy who put my new control
arms in tighten the bolts up, backwards, before the car was sitting on its
own weight)? Is this significant?
Any help will be greatly appreciated.
Richard
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