Hi everyone. I almost got my truck stuck before when I drove uphill on wet grass when I gave it a bit too much power and the rear tires spun digging into the ground. Upon closer inspection, one side had alot more grass and mud in the wheelwell than the other and I noticed as I drove off that the mud track was longer on one side and more mid chunks were coming off that same side. I notice that sometimes if I spin the rear wheels in mud briefly (I let off the gas as soon as I notice spinning) only one side spins. I know this truck is supposed to have a G80 (says so on the glovebox sticker) and the mechanic who changed the rear differential fluid last year said he had to add Posi additive because it is one, but I have never actually had both tires spin at the same speed on ice, snow or mud. I just had the truck in the shop a month ago for a pinion seal (2nd one in 8 months and I don't think that the seal that was on there was original since there is old gear oil from before 2007 on the body and gas tank) and the vents were plugged. They polished the yoke, replaced the seal and opened the vents and the leak is fixed. But could I have a problem with it or am I just not letting it spin fast enough to force it to lock?

 

I was wondering the same thing since i wanna upgrade to an g80 in the future

 

The Eaton Gov-lok rear differential (aka G80) that is used in these trucks does NOT need any special additives. It is NOT a conventional positraction differential.

To get a G80 to lock, there must be ~200RPM difference in wheels speeds. Also, a G80 will not lock once you are traveling ~25mph or faster.

I wouldn't go through the hassle of swapping in one. There are far better options out there that are stronger.

 

thanks for the information kyle

 

No additives? Wow. Could additive use have caused damage? I had them put Lucas 80W-90 in there (not the oil stabilizer, the gear oil).

200RPM difference? I don't even think the wheels were moving as fast as 200RPM in all cases where I only had one wheel spin. It takes that much of a difference to lock? In that case I am not being brave enough to push it to locking it seems like. I try not to let the wheels spin because I don't want to have parts in the axle or transmission break.

Thanks for the advice.