300M clunk

Many parts have been replaced in the front end of my 300M 1999 to eliminate
a clunk that started with a problem with front left strut. Most were done
under the extended warranty including steering rack and front struts. They
just replaced the bottom half of steering column and the left strut again
and the left strut bearing. Clunk is now much less frequent and takes a
good 10 miles of driving and a left turn to get it to happen. May also need
to be going up a driveway during the left turn. Also seems weather
dependent because some days it seems less likely to clunk. The dealer is
grasping at straws. Any guesses from you guys?

 

Is the noise more noticeable in the cold?

Ken

 

a previous poster had mentioned the same problem and it turned out to be a
loose hood hinge? Be worth checking and good luck.. RG

 

I got with a 300M owner last weekend that had a clunk (the 300M - not
him) that he couldn't nail down. He was ready to go into the
differential thinking it was related to the play in the output shaft.
We duplicated the noise by rocking the car backwards and forwards with
it in park while the other one got under the car and watched, felt, and
listened for a source of the noise. Turned out that the bolt that
secures the control arm to the chassis was slightly loose so that when
forces on the control arm changed direction, the control arm bushing
sleeve clunked (twisted) against the bolt and/or the chassis bracket -
he tightened that bolt - no more clunk. Your noise sounds like it is
from side loading rather than fore-aft loading from hard braking like
his problem was, although when I asked for details last week you acted
like how did I expect to be able to tell anything from your description
when you nor the dealer hadn't been able to isolate it after spending
tons of time and money on the problem.

Your problem could be as simple (and cheap) to fix as tightening up a
bolt that isn't quite tight enough. Is it possible that someone (or two
people) could jostle the car as violently as it takes - again, in your
case, it sounds like a side-to-side issue - while another person is
underneath poking around, listening, feeling, watching? Something has
play and is shifting when the forces change direction. Think in terms
of creating that change in direction to re-create the clunk and then
identifying where it is coming from. I could name a bunch of suspension
parts to check - basically all suspension and engine cradle joints,
bolts, and bushings - but applying that force to duplicate the problem
is the key. Once that is done, it's only a matter of minutes to put
your finger (literally) on the offending part(s).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

We have had the nuttiest winter in NC this year. It is currently 65 degrees
out. If it would get cold I'd have a clue.

 

Thanks Bill.

I've tried jostling the car around to duplicate with no luck because the
problem is that in 10 miles of driving with various turns it only happens
once so it is virtually impossible to duplicate. It used to be much worse
and regular but now it is rare but it is one hell of a clunk when it
happens. I will have them check out the bolt you mentioned.

 

I had a similar clunk with my '95 Concord for several years which was
gradually becoming worse. It was always when turning right into some
driveways, but had become more frequent including when turning right on
leaving my driveway after backing out and on some bumps along a rough
road.
Clunk now totally gone, after a smart mechanic discovered the inner
right tie rod end badly worn. The mechanic suggested it could also have
been slightly loose. He said they are a high wear item.
Relief, quiet as new again.

 

On the first LH series like yours, rear AT mounts could also cause clunks,
noise and vibration.

 

Just got off the phone with my service writer at the dealership who I've
know for over 10 years. I had left messages based on suggestions here. He
assured me that they have tightened and retightened every part they've
touched and any related part. The service writer and shop foreman have
taken long rides in it together trying to figure out where the occassional
clunk is coming from. So far still no luck.