I have a 90 4runner, completely stock as far as I know... But i have noticed when Im driving on snow or ice only the right rear tire spins unless i purposely spin the tires or start to slide the left will start to spin.. Or if I'm at a stop light and rev it and dump the clutch both tires spin.. Is this normal on a 90 4runner?

 

You have an open rear axle/diff. Power shifts to the wheel with the least amount of traction. This is how you get stuck in the snow or mud. Lockers and LSD force power to the traction side to get you out of a jam.

When you dump the clutch under power you are sending so much power to the axle that it breaks both tires free.

 

Is an open rear axle good or bad? I have never been stuck in snow or mud. And I've driven through snow that was 2 feet deep in 2wd..