87tq differential fluid

[Joan Kotjarapoglus <jkot+@pitt.edu>]

On very cold morinings - below freezing - my car growns when i am backing
it
up  and  it is very hard to shift  until I travel several miles.  A couple
years ago, I replaced the fluids with a blend sold by Blau.  I think it
was in part a sythetic blend.  Supposedly, it worked better it the cold,
but I did not find it so.  I want to change the fluids again in the hope
of curing the groaning noise and stifting.  Is there a full sythetic
blend that will solve my problem (brand?).  Will it cause seals to leak?
I would appreciate hear of any similar experienc and what sucess you may
have had in curing the problem.    Georg K   jkot@pitt.edut