Trans problem in Chev S-10?

[SOOT]

I have a 99 4WD Chevy S-10 with an auto and about 56,000 miles on the clock and when I put it in reverse it vibrates bad and the more pedal you give it the worse it vibrates :{ It shifts fine in drive and does not vibrate at all. The vibrations will go away if I run down the highway for a while and get the trans good and hot. It does not feel like it is slipping.



Thanks.

 

[Will24]

Doesn't sound like anything internal, maybe a converter or even just a bad u-joint