Pinion gear?

[PATRICKH]

Pulled in driveway tonight and rear axle made a loud clunk..If I try to turn the truck while moving, the rear tires chirp. I jacked the rear of the truck up and tried to spin the tire on the driver side and both tires turn the same direction with a grinding sound.

How screwed am I?

[HenryJ]

Time to upgrade to a ZR2 rear axle.

I think I still have my old ring and pinion, but by the time you buy the install kit and have it assembled you are going to be in it the price of a bigger, better ZR2 axle.

[PATRICKH]

Thanks for the offer. I gonna wait and see what the shop says and go from there. If it is a ring and pinion, think I'll get away for less than $500?

Why is it the big things always break when the budget is tightest?

[HenryJ]

$500 should do it if the carrier is good. You can probably get a good used axle for that too.
My guess is if it is just a pinion and ring, you will be under $400 installed. If the carrier is gone and it is a G80, you're gonna be $$ short.

Let us know what you find. Many have had water in the differential if they did not do the vent hose relocation recommended by the TSB.
I had the pinion shims "squish" out of mine. That led to excessive pinion slack. I caught it before it did damage, but was not willing to take another chance on the weaker 7.625" differential. I was able to upgrade to the 8.5" ZR2 rear axle for the same money. Total cost for the swap was $509

[PATRICKH]

Thats in the budget... Ill post as soon as I find out what went wrong.

[killian96ss]

If both wheels spin in the same direction when you turn one wheel and your tires are chirping when you are turning, your rear differential must be locked up. Broken teeth on the ring or pinion will sound horrible when the teeth skip the damaged section. Maybe your G80 broke and locked the axles together? It's also possible a tooth broke off and lodged itself inside the G80. Let us know what you find in there.

Steve

[PATRICKH]

Ok, here's what we found. I went to the garage and we pulled the diff cover off. No damage and everything looks good. We were scratching our heads at this point. The guy that owns the shop went to turn the driver side tire so we could spin the ring gear and it (the tire) wouldn't budge.

We pulled the wheel and discovered that the driver side brake caplier would not release. I broke open the bleeder valve, and we backed the piston in and clamped off that brake line and the wheel turned with no noise whatsoever.

Put the cover on, checked the vent hose, took it for a test drive. No noise, and everything seems to be ok.

He seemed to think that the caliper freezing would be enough to cause the problems. I'm not sure, but the dude's been in business (transmissions) for 30 yrs. All I know is it seems to be fine now.

[HenryJ]

Stuck caliper slide pins are notorious. Pull the calipers ,clean and re-lube the pins when you replace that caliper.

[PATRICKH]

Oh yeah, thats for sure. Learned that one a long time ago. Looks like it was the piston. Replacing everything tomorrow...