Differential locking up

[Z45]

¨ Optional Equipment (G80 Order Code) on all GM two-wheel and four-wheel drive light trucks and sport utilities.

Benefits

¨ Improved traction differentiates the vehicle relative to other rear wheel and four-wheel drive vehicles on the market.

¨ Maintenance free; requires no lube additives.

¨ Enhanced towing and off-road performance.

¨ Patented carbon friction disc technology enhances performance and durability while reducing warranty claims.



Principles of Operation

¨ Wheel speed difference (left to right) in excess of 100 RPM will cause a flyweight mechanism to open and catch a latching bracket.

¨ The stopped flyweight will trigger a self-energizing clutch system, which results in the cam plate ramping against a side gear.

¨ Ramping increases until both axles turn at the same speed (full lock), which prevents further wheel slip.

¨ At speeds above 20MPH, the latching bracket swings away from the governor and prevents lockup from occurring.



Technical Specifications

¨ Automatic locking takes place within a fraction of a second, so smoothly that it is unnoticed by the average driver.

¨ Unlocking occurs automatically, once the need for improved traction is gone, and is unnoticeable to the average driver.

¨ Compatible with anti-lock brake systems.

[BlueCrayon]

Just had this happen myself the other day....I was pulling into my parking ramp at work and there was a little ice when I pulled away from the gate, so I believe it slipped one wheel and it locked....problem is it didn't unlock so I was trying to turn the sharp corners going up the ramp and it was chirping/hopping all over the place! It unlocked when I kind of floored it for a second.

[kstruckcountry]

To unlock it, you let off the throttle.

 

I wouldn't be surprised if what the OP experienced was a front wheel "scrubbing".

 

Sent from my SM-G920V using Tapatalk

[Bikemobile]

It sounds like your truck is in 4hi when it says 2hi. There was a tsb/recall for that.

 

The G80 is mechanical, not electrical. It works independently from traction control and the 4 wheel drive system.

 

It works very well though. I'm on my 4th G80. 100,000 plus miles on each without any issues.

[sloz71]

Mine does it when I pull out from my friends street. You can hear the inside tire scooting on the asphalt. I don't even worry about it.

[Bmz72]

Common issue with the G80 locking diffs, it isn't normal operation. There used to be a TSI on the older ones, I would assume it could be applied to the newer ones as well if there isn't one specific already. Going off memory so don't quote me... drive the truck in several figure 8's in the same then opposite direction, then drain and service the rear axle with the specific fluid as it is not a limited slip, but a locking diff.

Good luck!

[Krusty]

I most def could feel the G80 Eaton Locker kick in on the 2007.5 Duramax rig - Would not own a rig without the G80..........

 

 

 

[vtwin63]

I had this happen about 4 days ago in a 2016 Silverado 1500 LTZ Z71. I had a friend at work with a ford that said i couldn't do a burn out. In the parking lot at work I did about a 5' burn from the stop position then let off. After that the rear diff was locked up. I went around the parking lot a few times in forward and tried reverse to park a couple times it was still locked up. It was making all kinds of scratching nose as the tire was scrapping on the assfalt and loose debris on it. I new it was locked up. So I was thinking ****!! So when I got off work and was leaving it was still locked for a second then I heard a clunk and it is normal again, its slipping around turns. WTF happened I do not know. But it was  locked for a little while and that is not normal.

[SierraHD17]

Probably damaged it a bit and the lock plate that locks to the side gear got stuck thus keeping it locked... those things are such mickey mouse pieces of junk.  Shock load to engage while under power is such a wonderful design.  Paperweights since 1973!

[badge171]

Back in the day, 70s-80s GM had a rear end additive, for posi-traction . The additive was a lube . As I remember couldn't have been more than 3 oz. bottle. Stopped the wheel lock up around turns, Just a thought  

[SierraHD17]

2 hours ago, badge171 said:

Back in the day, 70s-80s GM had a rear end additive, for posi-traction . The additive was a lube . As I remember couldn't have been more than 3 oz. bottle. Stopped the wheel lock up around turns, Just a thought  

The G80 is a locker and not a limited slip.  Gm has had bulletins out for at least 30 years now telling people to use oil with no limited slip additives as it just impairs the unit from trying to lock.  It wouldn't surprise me if they screwed that up back then and have been back peddling ever since.  You want it to lock lol... mind you most people could drive with an open diff and honestly be better off lol.