installed a junkyard tranny in my 1998 zj, tried it around the yard and on my dead end street ,all gears worked great, just got back from the first trip on the highway, worked great, but backing into my spot in my yard when put into reverse my rpms dropped under 400 and the jeep started to shake seemed like the engine would stall, tried going ahead worked fine, tried reverse, same thing, any ideas or input greatly apreciated i only have a limited time warranty on the tranny.

 

if it didn't have this problem before i'd say it's the trans. I've heard of the torque converter causing this problem,is the fluid level ok?