Rear Wheels Intermittently Locking 2001 Silverado Z-71

[killterrorists]

I have a 2001 Silverado Z-71 with about 170,000 miles on it and 275/60/R20 tires. I took a 1200 mile roadtrip last month and everyting was working fine on my truck when I returned. I

 

only used 4hi twice to drive through some deep snow. The day after I returned I noticed the rear wheels would lock up upon making a turn. The inside wheel would lock up for a second

 

then turn, then lockup, then turn etc. while the outer wheel would turn normally. On straight runs things were fine. On the second day after I returned I noticed that on a straight run the

 

rear wheels would both lock up then turn, then lockup, then turn etc. These conditions were observed on snow, ice and dry pavement. I also noticed a very definite extra load on the

 

engine when the wheels locked up. I just parked the truck in my yard for now till I have the money to fix it. I know next to nothing about working on a vheicles transmission or rear end

 

gearing. So I'd like to hear opinions from anyone out there on what the cause might be. I'm hoping that it's rear end related and not a transmission problem.

[pwall]

Almost sounds like the locker is gone south on you.

I'm assuming it has a G80 since your truck is a Z71. Check you glove-box and see if G80 is listed on the label with the RPO codes.

[ColoradoSkiCountry]

Yup your G80 Rear Diff has gone kablooey. Expect to pay some good $$$ to have a new one/rebuilt one put in. Sorry man, been there and at only 90,000 miles too. Sucks.

[hockeypro1411]

Sounds like a trip to the junkyard is in order.

[dlstewart01]

It will lock and unlock on snow and ice but should do it on dry pavement.

[killterrorists]

Well if the G80 went bad I'm not gonna have it rebuilt. Pretty dissapointing to have it go bad with 170,000 miles on it but then again I have brutally abused it on many occasions. I have

 

towed over 5 tons while hauling 1.5 tons in the bed, the airbags kept it level. And off road I've hammered it pretty well too.

 

I'm thinking of having a Detroit True Trac LSD installed or mabye a Eaton E-Locker although Eaton made the G80 which didnt hold up so well. My truck is mainly a daily driver with some

 

towing and mild off road thrown in the mix.

 

Any recomendations on a replacement diff I really dont want to rebuild the stock G80 when I now have the oppritunity to upgrade to something better. I mean I'll be paying for labor either

 

way so I might as well throw a better part at it.