[TR] TR6 tranny sound?

[Tim Gaines]

I thought I was leaving for a nice drive of about 150 miles in the 
TR6 a few days ago, but I didn't get farther than the gas station 
before some nasty noises turned me right around.  When taking off 
from a stop I get a crunching sound plus a "zzzup" thrown in once in 
a while.  My first thought was that I had a stone or two from my 
newly graveled driveway sitting on top of the drive shaft.  But I 
also thought it could be the tranny or the differential, and I didn't 
want to take any chances out on the road.  I got home okay.  In fact, 
the car ran smoothly once up to speed.  It only made the sounds at 
takeoff.  I got it up on jackstands and couldn't find any evidence of 
stones or loose flange bolts at either end of the drive shaft or at 
the rear axles.  I also couldn't reproduce the sounds with the wheels 
off the ground, either with the rear  wheels under power or by 
turning the front ones by hand.  I also couldn't feel or hear 
anything when I turned the rear wheels by hand or the drive shaft 
with a wrench on the flange bolts.

When I got the car on the ground and found that it still made the 
sounds (no lucky fix!), I started thinking it might be a disc brake 
pad issue.  It seemed like the sounds were coming from the 
front.  Today I replaced the pads and the nasty looking anti squeal 
shims.  In the process I rotated the rotors with and without pads in 
place and got no noises.  However, I did get something like the 
"zzzup" noise when I deflected the rotor guard into the rotor while 
turning it.  After everything was back together I made sure that the 
guard wasn't touching the rotor before getting the car back on the 
ground.  Just took a drive up the road, and nothing has changed; 
crunchy noises and "zzzups" at takeoff, forward and backward, but 
fine after it's up to speed.  I think I can feel a little something 
through the shifter when the noises occur, but I'm not really 
positive about that.  I also think that the noises stop when I 
disengage the clutch, but by the time I reach speed enough for that, 
the noises are usually gone anyway.

So folks, what am I up against?  Does a transmission make those kinds 
of noises when it's failing?  Is there something else I should be 
looking at?  Thanks for any help you can offer.

Tim
1974 TR6
1980 Spitfire