Rear end problems

the truck has approximately 175k miles. The gear lube has been changed about 6 years ago. Ok have another question. I think that there is a problem in the rear end. It is locking up and causing the truck not to be able to back up. I had put power stop rotors and brake pads on. So I thought that the back up problem was the new rotors and brake pads on the rear brakes was the cause. So I put the original rotors and bake pads back on. The problem is still there. I can jack up the rear of the truck, but some times I can't spin the tires, other times the tires spin freely. So I am thinking the problem is the rear end. Is the common problem.

I would check for stuck/sticky caliber pins first.

I would check for stuck/sticky caliber pins first.

The caliper brackets and the caliper slide pins are about 1 year old. When I pulled off the caliper brackets I pulled the slide pins, and the pins came out very easy.

I see that I did not mention is going in reverse is when the problem shows up, going forward there is no problem. Also the parking brakes are not the problem either when the rear brakes were done the parking brake shoes were bad and I did not replace the parking brake shoes. I could not afford the $150 for the pair of parking brake shoes.

You need to diagnose whether brakes are causing this or the diff, do you have the G80 locking diff, the rpo codes should be in the glove box, check and post back.

the truck has approximately 175k miles. The gear lube has been changed about 6 years ago. Ok have another question. I think that there is a problem in the rear end. It is locking up and causing the truck not to be able to back up. I had put power stop rotors and brake pads on. So I thought that the back up problem was the new rotors and brake pads on the rear brakes was the cause. So I put the original rotors and bake pads back on. The problem is still there. I can jack up the rear of the truck, but some times I can't spin the tires, other times the tires spin freely. So I am thinking the problem is the rear end. Is the common problem.


the fluid gear oil replacing is done by removal of the cover and cleaning and inspecting the gears. since it has been 6 years my guess is this is well over due. check for damaged gears. check out the wear marks on teeth. see if the gears are binding by rotating the drive shaft in reverse both tires Off the ground. push back rear brake calipers first.

if you find that you have a G80 locking diff and its in need of replacement make sure you breakin the new diff over the first 1000mi. no heavy or long operating periods esp at hywy speed. then at the 1500mi clean box and replace the diff fluid.

during breakin the gear teeth are hardening and gear fluid temps rise , this is why the fluid needs replacing at 1500mi.....

j cAT I found the sticker on the glove box door. It has like 50 different codes do you need them all.

j cAT I found the sticker on the glove box door. It has like 50 different codes do you need them all.

give vehicle details engine / drive train etc...year ..


does the RPO codes show G80 ?

You have sticky caliper.
Look at the rotor. Is it blueish tint? If yes, then that is the side with sticky caliper. Replace. It's cheap and quick job.
Or, cuz you have beat up parking brake shoes, they bind on the rotor inside when backing up. I just did mine on my Silvie, it was $57 parts and 20 or so minutes per side. At least I have SOME parking brake back now.