I have a 05 Chevy Avalanche 2500 with a stock 4.10 locker rear end. At least once a year I have to change the rear diff fluid because of binding when turning.

I use the synthetic oil that GM recommends and everything is fine after the oil change but the more miles that pass the rear end starts acting up. It completely locks/crunches/bangs on really tight turns.

Is there anything that can permanently fix this or is this just part of regular maintenance on the GM locker-diffs.

Sounds like it is going south. I would imagine that truck has the 14 bolt rear in it being a 2500. If you have the locker it is the g80, they are notorious for breaking.


John jr

What happens when it "goes"? Will I have warning? Getting ready for a big 6 hour tow and was just going to do another quicky fluid change.

It's been behaving like this for 6 years.

When my locker went it was doing the same thing. It was fine going in a straight line but making turns it would feel like the rear end was getting ripped out of the truck. At first I thought it was the axle bearings, but after pulling my diff cover it was the actual clutches and all that was gone. Does any metal or shavings come out with the oil you drain?

John jr

if you have the 3.5 x13 brakes with the semi floating hubs then nothing will happen,that style rear end it will either lock solid or it will act like a open rear end..just so you know after changine the fluid it reads on the back of the bottle that its for limited slip diff'd..you also need to add a tube of posi lube but i add 2 tubes to mine to get it to stop making noise...

Keep a eye on your tires because if it locks solid your rear end will bind and ware the the tires out...if its binding now when driving try backing up a few hundred feet to unlock the posi.

GM has a posi fluid additive in a 4 ounce bottle- try adding this. The synthetic does not have enough of this in it. I have the same truck and axle.

Wannabe

ECHO!!

STOP BANGING ON ME FIXX I hear yah!!!!!

LOL