locking diff woes

[NelBosco]

'03 Silverado LT with G80 just reached 20k miles. Yesterday it was raining here in NYC so I may have spun my wheels. Anyway, while turning down the street to a parking lot I noticed a groan coming from my rear-end I thought I had 4wd engaged but it was in 2wd. Reached the lot and turned into driveway and confirmed that one wheel was screaching/scraping I think diff was locked. Pulling into the parking spot was also and sensory experience. On my way home it seemed to unlock and was driving normal after about one block. This morning, raining again, I spun my wheels and this time I heard a slight chatter while diff engaged around a bend after this the rest of the drive seemed normal as I spun my wheels srveral more times. I made a service appointment but would like your opinions on whether the diff will soon be toast or will fresh fluid save the beast? Would like some info before I take it in for service.

Thanks..

[frdfandc]

I had the same thing happen to me a couple of times. I currently work with a former GM technician at the dealer I work at. He said that is normal for the G80 locker to do that sometimes. Just a characteristic of the locker. Actually mine did this this morning on the way in to work. Went around a turn (it was raining this morning) and the locker engaged. Took another 2-3 turns for it to unlock.