At 01:00 PM 12/31/70, Frank Herzig wrote:
 > My 85 Vanagon with 180K miles has a thump when I hit any minor bump in
the
 > road. It sounds like something hitting the frame under the passenger's
seat.

And Dave responded,
> I would look at the bushings for the upper control arms first.   Bentley
> tells how to see if they are worn, but the easy way is to unbolt the
upper
> ball joint and see if anything is loose.   I'd bet that either the
control
> arm bushings or the upper ball joint (s) are bad.  Neither are hard to
> replace (assuming you replace the whole upper control arm.)   Someone on
> the list (Ron Salmon at Bus Depot, or maybe Kyle Wade) had upper control
> arms for sale at a very good price not too long ago, and I replaced them
on
> my 87, along with upper ball joints, and the clunking is miraculously
gone.
>
> For the record, Unca Joel said it was probably the bushings.  I said Nah,
> it sounds like ball joints,  I know what worn ball joints sound like.
But
> he was at least 80% right, cause the bushings had noticeable play.
Maybe
> the ball joints were worn too (a little loose anyway).   I replaced them
> anyway.   Made me feel better.  Check the bushings first.

For what it's worth, my personal experience has been that bad upper ball
joints clunk and bad upper control arm bushings squeak (for lack of better
words). I've heard of worn ball joints separating catastrophically in
certain instances (hitting a pothole, etc.), while on the other hand I've
seen upper control arm bushings make noise for quite some time but
otherwise otherwise not cause a problem (other than driver-irritation).  Of
course, your mileage may vary.  At 180k miles, replacing both may not be a
bad idea if you're planning on keeping the van a while, although it also
may not be absolutely neccessary.
I do have a deal going on right now on German upper control arms, as well
as the bushings alone and German ball joints.  Won't waste bandwidth with
specifics, but of coure you can always e-mail me directly.

-Ron Salmon
 The Bus Depot
 http://www.busdepot.com