Need advice about A904 noise in reverse

A local shop installed a "reman" tranny in my '79 Volare with Super Six and AT. That was in December of 2010. It had a 1 year warantee.

Murphy's Law got me. I've been unemployed for quite a while. I'm forced to sell the car to pay over due bills, so I posted it on Craigslist locally and the next day the tranny started acting up.

It makes a sort of howling and grating noise when I put it in reverse, but only when the car has not been run for 4 or 5 hours or has sat overnight. It does not slip, and does not make that noise in drive. If i drive it for 15 or 20 minutes and stop and put it in reverse it does not make any strange noise. The fluid level has been checked and is correct. It upshifts and downshifts fine, it backs up the car even when the noise is there.

I thought maybe somebody had experienced this problem and could offer some advice or an educated guess. Kind of hard to sell a car with this going on.

Thanks.
Author: MrRoute66