tranny

I got a 2002 auto when you put it in reverse it feels like it needs a trans mount or something. but it dosent happen in any other gear.

You probably do need a new Trans Mount. Open the hood and have someone watch the engine, put the car in reverse and lightly step on the gas, if the engine rocks forward a good amount the trans mount is bad and needs replaced, usually you will also hear a "clunk" and feel it in the floor if when in the reverse you stab the gas like you are trying to back up kind of rapidly, or if you place the transmission in low gear and run the speed up to 30 miles per hour and bail out of the gas abruptly you'll hear the clunk too. All signs of a bad Transmission Mount.