'87 4000 Quattro CLUNK!

[urquattro]

I guess I haven't kept up with the thread to know what has and has not been
suggested.  One of the least followed maintenance requirements for the
quattros is the 15K mile service interval on the u-joint in the propshaft.
My V8Q was making a similar noise when I bought it ... a shot of grease into
the U-joint cured it.  A 4kQ's UJ is a lot easier to access than that on a
V8!

If that does not cure the problem, please don't go full freight on a new
propshaft ... they are very easily rebuilt.  I posted my procedure for
replacing the carrier bearing on the shaft on my urq years ago ... I don't
have a copy on this computer, but if you can't find it in the audifans
archives let me know and I'll dig it up.  Since those days replacements for
the CVJs at the ends of the shaft have become available too (a fact I
thought I had posted recently).

HTH!
Steve Buchholz
San Jose, CA (USA)

> I have seen many letters in the archive with the identical problem to
> mine.  The advice is almost always to check the rear differential and
> subframe bushings.  I have checked all bushings, ball joints, and tie-
> rod ends mine and they are in good shape.  I can't believe that this is
> a rare problem because I have two 4kq's and they both have the exact
> same clunk.
>
> There is one archived letter inparticular which describes my problem
> well.  It is at http://www.audifans.com/archives/1998/09/msg00069.html
>
> The advice to him was to check his rear diffential mounts.  In addition
> to his problem, I should add that if the driveshaft is twisted quickly,
> there is a metallic "ping" sound.
>
> I took the car to a mechanic today.  He drove it, put it on the lift,
> and told me that it was a bad driveshaft and needed to be replaced.
> Before I fork out $500 for a rebuilt shaft, I want to confirm this
> solution.
>
> I have never seen a letter on the list that said that a new driveshaft
> had cured their clunk problem.  Those who have said their clunk was
> fixed have had a bad mount or bushing as a problem.