I've been hearing a thump.  I think it's my transmission.  I just got this
4-spd from a 90 vanagon at the auto salvage yard. Anyhow, this is what the
conditions are:

I hear a thump, thump, thump when I'm in third gear an accelerating. Only in
third gear.  The frequency of the thump seems to be about 1 per-sec at
around 40 MPH.  It is not thumping as fast as the engine is turning, nor as
fast as the wheels.

Any thoughts?  I guess I should get ready for a rebuild? I have a core
sitting in my garage with the broken 3/4 slider problem, now this.  I'd love
to be able to trade them both for one good one.

Bradley Flubacher
State College, PA