I would like to see if I can find any information on this problem before I replace/rebuild the differential. I searched and found only one other thread with this issue and it was never resolved. My car is a 2004 6mt. I do not drive this car much as it is a track car, however I try to start and run it a couple times a week to warm it up. Today, I let the car warm up and made my way out onto some local back roads, I shifted down from 4th to 3rd(only at about 40mph) when the problem first occured. I felt what seemed to be loss of traction, but then realized the rear wheels had locked up. At that point I was still unsure if that was actually what happened, so I continued to drive. On the way back into my neighborhood, I slowed down to about 25mph and shifted into 2nd when it happened again. The rear wheels stopped moving almost as if someone had yanked the handbrake up. I am waiting for the roads to dry before I go out and try to recreate this problem. If anyone has any insight, it would be a big help.

Also, the traction control light came on(and stayed on) after this issue happened the second time. It would not go off even if I pressed the button.