• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

G80 Not Unlocking


Full Member
Jan 26, 2005
Grant, MN (aka Stillwater, MN)
This has only happened to me once that I noticed. But seems to happen a lot to a coworker in his 01 Sierra 1500. The G80 locker will engauge and then not release.

The only time it happened to me it scared the crap out of me because I wasn't expecting it. I was dropping our daughter off at daycare a few weeks back and we had gotten a light dusting of snow on the side streets. I came around a corner and must have hit a slick spot and the locker kicked in. I drove down the road to the day care provider's house and when I turned into their driveway there was this loud bang, bang, bang and the truck kind of jerked. The road in front of their house was dry pavement. I wasn't expecting it and I knew I had a bad u-joint so the first thing that went through my mind was that I dropped my drive shaft. Well, since I was in 2wd and still able to go up their driveway I knew right away the drive shaft was connected. As I was getting her out of the truck I thought that it must have been the locker as I looked at the dry road and remembered the somewhat slick corner. As I left everything was fine so I didn't really worry about it.

My co-worker said he is more concerned about his as it seems to do it a lot. He asked if there was a way to disable the G80 locker. I didn't know but said I could ask here. He was wondering if there was a pin or something simple that he could do to his rear diff to disable the locker. He said he would rather have a one wheel wonder then have to deal with a grenaded G80. While he only goes mudding in his ATV he has a lot of buddies that go offroading in their trucks and many of them have blown their G80s.

Any ideas?
Raceman said:
Try stopping and backing up a few feet
ALso getting above 25 mph will disengage it
Crow-hopping in one's Av could be a bit embarrassing.

My S-10 did that a couple of times, among it's usual wheel-hopping on slippery stuff. I just backed up while turning side to side and it unlocked. `Didn't take much of that maneuver.
Flush and refill the rear diff, have had good results with that procedure with g80's at the dealer....
Raceman said:
Try stopping and backing up a few feet

This is what I was thinking too, Most locker will dis-engage when you drive back wards.
SamHouseIII said:
This is what I was thinking too, Most locker will dis-engage when you drive back wards.

Yeah for me it fixed my issue the one time it happened. When it did it I was pulling into their driveway so I had to back out anyhow.

My co-worker has seen some blow up and I have read of this happening here as well. That is why he just doesn't want it anymore. The other comment he had is he doesn't like how hard it hits when it locks. I don't seem to have that problem. I'm not sure why. Maybe when I spin my tires they are going faster then 25MPH so it never locks. I know I have spun one wheel and it does not lock. I also know my locker works because of other times where it locked up and like the one time didn't have a chance to unlock because I never went over 25 or I could feel the back end start to slide around more than normal.
It happened to me several times when I leave work in the winter. I hit ice when making a left out of the parking lot and the red light it right there. Then when the light turns green 5 minutes later :E: I swing to make a left, and I hear it not letting the outside tire spin quicker and it hop around the corner. I think its because I do not get up to 25 after it engages before I stop for the light. I never had it happen anywhere else and it always dis-engages after that :love: