ppolattie

I have looked through the threads but not have found any regarding my current situation. Car: 2000 Outback Limited 2.5L AWD approx 148K Purchased April 2012 I had catastrophic transmission failure. Mechanic said old tranny probably tore up differential because of axle and wouldn't be worth it to rebuild, so we took the old tranny out and put in a used tranny, filter and ATF looked clean as if it had recently been replaced. Got car back and bad news, it hesitates when you put it in reverse and try to back up. I also noticed it hesitates a bit at stop lights and stop signs. Reverse is worse than anything. Used recommended synthetic fluids I read the thread regarding ATF and Trans X. My question is would this fix the reverse issue or is reverse completely different from the forward motion tranny problems? Thanks for your help!