[Supras] Help! New vibration MKIII Supra Turbo - at72mph+ post mechanical work - update

[Dell Anderson]

Well, the mechanic, customer service rep, and shop owner met and determined
that it would be in everyone's best interest to have the drive shaft sent
out to another shop for analysis (the first shop sent it back very badly out
of balance, the first two times, the third time the 'cut and replaced' the
part that has rubber and replaced it with a non-OEM but OEM quality solid
part, something I learned about just recently.   Although the mechanic
reports the vibration is 20% better, if the drive shaft comes back "OK" by
the 2nd shop, they are recommending a $600 (parts only, free labor) repair
to some slightly loose parts at the output of the automatic transmission (I
had the transmission rebuilt about 5 years ago, but I don't know exactly
which parts were replaced).   I have asked them to hold off on that
particular repair until I can come down and drive the car and do a pre- and
post- repair comparison.

The shop antipated my concerns about wheel balance and stated that they had
put the car on a lift and revved the engine, and were able to replicate the
vibration that way, thus ruling out at least front wheel vibration.  I don't
know about rear now that I think about it.  I think they may have taken the
wheels off for the test but I'm not sure.

If I test drive it, it will most likely be this Friday.  I'll try not to get
a speeding ticket.

Speaking of which, another problem I've noticed (but dare not mention yet
because it would only cloud the issue) is what seems like a gradual decrease
in power compared to when the car was new.   I'm wondering whether there is
some kind exhaust system obstruction because when new the car had a lot of
kick to it and would lay me back in the seat without any trouble, as soon as
the turbo kicked in.   I haven't noticed any change pre- and post- this
particular repair though, so it will be a future project....

Dell