Chevy & GMC Vans

My van has the G80 locker and I noticed that the rear wheels seem to be locked all the time. I did some messing with tires this weekend and when either wheel is lifted off the ground it's locked. Is that the way it's supposed to be? Makes it handy for breaking loose lug nuts with a wheel off the ground.

If you have both rear wheels in the air and you spin one ( lets say clockwise ) does the other tire move in the same direction ( from your viewpoint ) or opposite?

If you had one wheel in the air only and the van in park the wheel will not move.

Kidhauler is right. Whether an open or posi rear, having 1 tire in the air and the transmission in park will not allow the free tire to turn.

To go along with astrozam, if you have both tires in the air and spin one CW, the other will go CCW whether you have an open diff or the G80 posi. The reason for this is the Gov-Loc posi only actuates under torque. Spinning by hand most likely will not produce enough torque to lock it up.

The G80 is speed biased, not torque biased. It should lock when there is approx 100 RPM difference between two wheels.

I was able to test my G80 by lifting all four wheels off the ground. I carefully held one wheel stationary with my hands while a helper operated the gas pedal.

The other way to test is lif one tire off the ground and block the axle if the truck drives off the block then the posi works.

That won't work with his AWD because the front wheels will pull it off the block.

Ya know,service with a fluid change wouldn't be a bad thing.So a visual with the rear cover off sure would confirm what he has.

I know the G80 is working, I just thought maybe it was working too well (like stuck in locked mode). Fluid change is in the near future so I'll be able to see what's really heppening in there then. Thanks for the comments!

If the rear axle was locked all the time, you would hear some tire chirping in tight turns.