Abot how much play in the axel shaft at the transmission is normal? I know zero is good, but I doubt there are any with zero.

It's a tough one to measure. I replaced my bearings when the axle wobbled about .100"..They started leaking too.....I am guessing that .050" would be OK.

If you wiggle one side do you feel movement in the other side? If so it is a sign that the differential bearings are going bad.
They aren't too bad to change. I just replaced them in the Getrag on my 88GT. I got Timken bearings for $12+ each. Don't bother trying to pull the old ones off. Just remove the bearing cages with a cold chisel then grind through the race until they crack and release.

[This message has been edited by Carrolles (edited 08-15-2013).]

It's not a lot and is the same on each side, no movement transfered from on to the other so I think life is good. Larry