I had my car on jacks today, and when I went to start it up I noticed that the driver side wheel was spinning...this isnt normal is it?

 

oOh phew...thanks...

 

why does it do that, is it the vibrations,centrifugal forces,etc? i noticed it for the first time in my friends rex.

 

When the clutch is out everything in the tranny is spinning. If the wheels are in the air there is not enough resistance and they just spin. You could easily hold one of the wheels and keep it from spinning as it is not directly connected to the engine in neutral. Not sure if I explanied it very well, but if you take apart a tranny it becomes quite clear.

 

engine is spinning the gears inside the tranny. This whips the oil along with some drag on the synchros and the wheels spin.

Really gets going when it is belowe zero outside.

 

Yes normal all due to the drag and friction of the oil and bearings in the transmission. even in nuetral there is some drag quite enough to get that boy spinning pretty good.