Left my house to go cruise around and visit some friends. I get to a stop sign and roll out easy with it in low and at around 25mph go WOT and it burns rubber like it never has before from a roll (it singled out and I have a G80) I was like WTF. Well next road I get to is one of those concrete roads that generally hook almost as good as a prepped track. While sitting at the red light a guy pulls up next to me in what looked like a 98 model ext cab that was LOUD, not good LOUD nasty LOUD. I look over and it’s this kid and he gives me a rev. The light turns green and I go WOT from Idle. My truck singles out again then it seems like the G80 kicked in and made a horrible clunking noise. I let out and went right back WOT and pulled about ¾ of a truck by 75mph. Next red light I stall it to around 1200 go WOT clunking noise again no spin. Stopped about a block from my boy’s apartment power brake, it singles out then start to spin positive with clunking noise again so I get out of it. On the way home I said FK it I’ll try it again I only got 12,000 miles if it breaks….warranty. I did 3 WOT take offs and no noise and never spun a tire. Has anyone else had this happen? Is the G80 broken?

 

Sounds to me like it's broken, if it's still under warranty I would take it in and have them replace it for you. The G80 is notoriously weak when putting any decent amount of power through it.

 

The Eaton Gov lock G80 stock GM locking rear diferential has a centrifugal device that prevents its engagement at speeds over 20mph.

If its making noise like that though, it probably is shot.
peace
Hog

 

what hog said

 

My g80 acts up sometimes, too. Off the bottle it will lock and spin both tires...put the juice to it and it's one wheel peel, even with slicks. I'm scrapin' mine for a spool.

 

I would say it's broken. I just keep my fingers crossed every time I go WOT on mine. I know is going to go but hopefully later than sooner.