UPDATE: How to ID faulty mount/driveline components?

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

I thought I'd provide an update since it seemed there were others that had
been seeing similar symptoms.  I also figured I'd fix the typo in the title
... :-)

Patient: 1991 5-speed V8Q
Symptoms: driveline shudder on occasion ... apparent link to spirited
driving ...

I went all over the driveline the other night and could find no broken
mounts, the only thing apparent was that _perhaps_ the carrier bearing
bushing was sagging a bit.  As I noted in my original post I saw that the
u-joint on the propshaft did have the grease fitting (Zerk).  I don't think
I've seen this listed as a maintenance item for the V8, and given that it is
hidden behind a heat shield, I doubt that it had ever been serviced (odo now
shows over 80K miles).  So ... I lubed the u-joint (which took a bit of
grease) and put it back together with my fingers crossed.  Limited testing
last night showed that the problem did not return.  I drove the car to work
today, and so far so good.  I think it is still a bit early to declare
victory.  I figure my next plan of action if the problem returns is to sit
in the trunk and watch the rear suspension while the car is moving.  (the
spare wheel tub was broken on the car when I bought it, and although it has
been replaced I did it in a way that allows it to be removed again fairly
easily.  Thinking about having to do something like this is more than a bit
disconcerting ... and reminds me of the time when I was much younger and my
dad had a difficult to isolate noise ... I remember driving down the street
while he hung out the passenger door and looked under the car to try to ID
the source ...

Perhaps if there is someone suffering similar symptoms and can easily
service the u-joint and report their success or failure back.  I'll provide
an update as well as time progresses ... but I'll be pretty quiet here for
the next couple weeks as we'll be on the ocean.

One other thing I'm considering is fashioning a stiffening ring to fit
within the fold on the carrier bearing housing.  I figure it might cause a
little more vibration to be coupled to the body of the car, but it might
also tend to kepp the propshaft lined up properly and reduce the magnitude
of any vibration.  I'd appreciate hearing back any thoughts or BTDT on that
idea.  

Steve Buchholz
San Jose, CA (USA)