Try a quick test by jacking up one rear wheel, releasing the parking brake, placing the car in neutral, and turning the road wheel. Then repeat this on the other side with the first wheel back on pavement. The driveshaft should turn for each test.
Now jack up both rear wheels,release the parking brake, and put the car in gear. Turn one road wheel. The other wheel should turn but in the opposite direction. Repeat for the other wheel.
Assuming no differential problems, it could be something as simple as having a dragging rear brake on one side.
: Question: I have noticed that one of my
: rear wheel spins easily on wet
: pavement. What could cause that when
: our cars are not that powerful? My
: tires have a lot of tread left. Is my
: differential broken? I have a 3:23 rear