Shimmy fixed

Well, I took the advice given here and today I jacked the Acclaim up to
check the CV's again. Like before, I couldn't really see or feel anything
that would say they were the source of the problem. The only thing that
looked a little suspect was that the boot on the inside passenger CV seemed
to be puffed up a little. When you squeezed it, it felt like there was
pressure inside. This made me think that maybe water had gotten into the
joint (as suggested here). I had been driving the car and it was hot. Any
water in the joint could have pressurized the boot.

Based on this and the advice I got here (on the board) I pulled the
passenger half-shaft for a closer look. Opening the boot showed that all
the grease was still there but that I might have a little moisture in it.
It's color was a little brown. I still could not see or feel anything wrong
with the joint, but since it was out, I went and got a replacement.

Short story is; problem fixed. The car no longer shimmies at the 38 - 45
mph range like it did. All I can figure is that (as suggested) the bearing
rollers in the tripod joint had worn the slide surfaces so that they were no
longer flat but indented in the same shape as the bearings (concave?).
Therefore, under acceleration, either the bearings become locked in these
grooves or they try and climb out of these grooves which puts lateral force
on the shaft and pushes the engine to the side (because the tripod can no
longer slide and do it's job).

The moral to the story is, you really can't see or feel this wear in the
joints. I guess experience (probably gained by trial and error) is what
will tell you where the problem lies.

I really appreciate everyone's help. I probably would have replace
everything on the car looking for the problem before I got to the CV's.

Thanks again. You have save me a lot of time and headaches.

David Dowell.

 

You're welcome. Truth is, it's common knowledge among mechanics and
many here that when problems like you were experiencing are dependent on
accleration and/or deceleration, the primary suspect would be a bad CV
joint - and usually the inner ones (also referred to as DOJ's, or
'd'ouble 'o'ffset 'j'oint - all DOJ's are CV joints, but not all CV
joints are DOJ's).

Anyway - glad you got it figured out and that we could help.

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

 

The color brown gave it away, if it got to that point the joint was toast.
The housing gets a deep groove worn into it and it causes the vibration.

Glenn Beasley
Chrysler Tech