Ok, I've had this problem since I bought the peice of shit. The trans is fucked to put it in easier terms. It's most likely the differential. 96 (?I think it was a 96?) GSR Trans, it will move the car in every gear and doesn't grind. The clutch is brand new and engages properly and fine, the slave is fine, the master is fine. The flywheel is fine, but I'm pulling the trans anyway so I'm putting my 8lb one on anyway. In first I have to rev it up to at least 2k for it to move, no this is not normal, it will not move an inch and will lock up if I try to ease off the clutch under 2k. After I finally get it moving it propells the car fine until about 4.5-5k rpm, then the differential slips (I can hear it, it's not the clutch). All the gears do work, reverse is a little hard to get into, but it makes the noise (keep reading) from idle to whatever engine speed. At 4.5-5k then the diff slips if it doesn't lock it up (it usually locks rather than slips), depressing the clutch releases this lock and continue to let the engine run and it will roll fine, obviously. It makes this horrendous sound, it knocks from around the differential area, really bad, it will continue to knock unless the clutch is depressed and you can still hear a rubbing or some type of sound in the differential area. I don't know what the hell is knocking in there either. The bold, this makes me think MAYBE it is the clutch because it continues to roll fine, but maybe not. Also, releasing the throttle will help but it will jump and lock up the wheels sometimes. Flooring it does nothing, it will not catch and holding the throttle will usually make the engine cut out as well, until it rolls/brakes itself to a stop. The engine is fine, it idles at 1k, revs freely to 6.8k in nuetral with the clutch enageged or disengaged. So my questions are: What would think the problem is with the described symptoms? How hard is it to replace a differential? Ive never worked on transmissions/transaxles before While I'm in there would it be worth replacing something else, it does not have any grinds in any gear. I will not bring the tranmission anywhere. I am buying another trans but everyone always can use a good condition back up. If I cannot do it myself, then I'm selling it.