I have some questions regarding rear wheel occasionally locking and making a clunk sound on the 240sx. Unfortunately the right rear wheel started locking up right after I pulled the car off the trailer last week at the track. That was my second time ever at the track and was excited to run the car in that HPDE but because the wheel started showing signs of locking up and occasionally making a clunk sound, I didn't run.

I thought it was the wheel bearing so I opened up the rear axle housing and took out the wheel bearing with flange and the wheel hub. I tried turning it with hand back and forth but it seemed like the bearing is fine. There is no noise and it wasn't locking or turning roughly.

Now I am not sure what might be causing the wheel to lock up. Also, before anything else, the wheel was only locking when i drove it in a circle to the left and the right rear wheel would lock up. Could this be caused by the Nismo Mechanical Locking Differential case that is installed in it? I am not sure about this because I thought that with the Nismo lsd the wheels should not lock like that when turning (or driving) in a tight circle like it would if the differential was welded.

I am just looking for some info about this as I am just a little worried because while on the track I was feeling a minor but somewhat abnormal vibration from the right rear that I never noticed before. I also heard an occasional clunk sound too. I am also not sure if it is normal for the Nismo Mechanical locking differential to lock up the outside wheel like that when turning in a tight circle.

Any info is greatly appreciated.

Thanks,