Limited Slip Diff.??
 

I have the G7 option Limited Slip dif. on my 02 Silverado but it's not working very good?? We are in a blizzard now and I notice only one wheel spins sometimes both but mainly one. I have 260K miles on the original rearend so I don't know what kind of shape it's in. Do you think it would make a difference if I changed the fluid and added new limited slip additive??

G7? Is that the RPO code from the label? I don't recognize it.

As for fluid changes, 260K is quite long for rear diff of any sorts. Fluid and friction modifier would be my first stop.

I may be off on the G7 code but that is what came to mind. It has had the fluid changed I believe a couple times but don't know when the last time it was changed.

The tag in the glove box revealed the truck came with the 3.73 gear and the limited slip but usually when you rotate one tire the other one should rotate in the same direction if you have the limited slip. For some reason mine rotated the opposite direction. Maybe the clutch pack is worn away??

Check the glove box again and see if you have GT4 (3.73) and G80 (locking rear diff) or something else.

That's exactly it...

I was somewhat stuck in my drive today and could feel the axle locking in then popping out. When it would engage that would enable to move a little farther. Weird??

That's exactly the same combo I have.

The G80 locking rear diff doesn't have clutch plates or use friction modifiers. When one wheel spins faster than the other, the G80 locks the axles. There are some threads around the forums on the G80. I don't remember exactly when the G80 would unlock the axle. Having it unlock and then relock if one wheel keeps spinning would be normal. The unlock point is the unknown point in my mind.

I would certainly replace the fluid (synthetic gear oil (75W90 I think), GM# 89021677) at 260K. No friction modified needed. I would use the GM stuff.

Don't remember if there is a drain plug or if you have have to remove the cover (and my truck is covered in 15" of snow at the moment).

Ok but what about the tire rotation thing?? Isn't true that on a limited slip when you rotate one axle the other axle should turn in the same direction?? Or is that with a true posi??

There is a good video at YouTube for the G80.

And a great demo video as well