I may purchase a car that has a mendeola md4 and a jamar shifter. I have not yet drove the car but the owner tells me reverse pops out after a couple seconds. He says there is no grinding in reverse just a thud when the gear slips. There are no problems in any others gears. I was told the culprit is the jamar shifter and that rebuilding tbe jamar or buying a proam would solve the problem. I am new to these transaxles and cars as I have had utvs and trucks. Any advise on this would be appreciated.