Drivetrain lash

[David.Payne at brinksinc.com]

This is a little hard to explain but I'll give it a shot.  Ever since I got
my 89 90q it has had some "looseness" in the drivetrain.  You can feel some
movement if you let off the gas and it feels like it is taken up when you
get back on the gas.  In the taller gears it isn't very noticeable, but in
1st you feel it and hear it.  The noise is a ringy clunk, or maybe a clang.
While tightening a loose heat shield last night, I grabbed the driveshaft,
rotated it by hand, and was a little surprised by how much it would turn.
Rear end was off the ground, ebrake off, in neutral.  As I take up the lash
in the driveshaft, the noise I hear on both ends of the travel, is similar
or the same as the clang that i hear when I'm driving.
My question is; how much slop does the torsen have in it?  This car was
involved in an accident before I got it (that's why I got it cheap), and I
suspect that the transmission mounts are shot, and possibly the hydraulic
motor mounts as well.  How do you know if the hydraulic mounts are bad?  I
mention the info about the mounts because the lash I have could be normal
and the noise is because the engine/gbox are moving around to much.
Thanks,
Dave.