I think the open differential will work. Once you change out the backing plates and brake hardware it should bolt right in.

 

What year is the replacement axle from? Drum brakes sounds like a GMT400 maybe?

The differential will work (fit) but i think the spline counts may be different. May have to swap axle shafts over as well.

 

G80 strikes again! Exact same story with a guy I work with. He spent $1200 having his fixed. Sounds like open is the way to go. Otherwise you can pick up a $200 lunchbox locker for the new axle. Or else a new carrier and gears if you want to keep what you have but plan on at least $1000 for that.

 

What year is the replacement axle from? Drum brakes sounds like a GMT400 maybe?

I'm not even sure yet, it was a buddy that found it for me, I have yet to talk to him in person, but did they not convert these trucks back to drums in 2005 or so?

 

Or else a new carrier and gears if you want to keep what you have but plan on at least $1000 for that.

Yeah I am really not prepared to spend that kind of money right now. I only spent $4000 on the whole truck lol. Sounds like I'll probably be swapping in an open axle. I have looked up aftermarket drop in lockers, but really, I don't even care if I have a locker, I just thought that if the truck came with one that it would be good to keep it that way.

 

Local shop quoted me anywhere betwen $1000 and $2000 without seeing it, depending on howm uch went wrong inside there. I think I'm just gonna look for a used one. Now I just need to find out what years they fit from, and if drums and discs are interchangeable. Anyone have that kind of knowledge?

 

Any junk yard should have an interchange book that will tell them what years will work.

 

i wished theyd never used the Gov-bomb in the first place.. its scrap from the beginning

all 10 bolt rears will work. the differences are the older they get, they switch to 1/2" studs. and the different widths on the spring perches. you can get a used axle for a salvage yard for barely a song and dance. $2000 is way to expensive in my book.. you can put all new brakes on a 10 bolt, new u-joint, fluid, seals, and new u-bolts for under $500... not sure what the rest of the cost is for.. install, is 4 - u bolts, hook up brakes and a drive shaft.

 

Local wrecker that I've dealt with for years has the exact same rear end with a G80 (grrrr) and want's $400 for it complete. Swears it's a good rear end because he personally drove the truck. Im a little leary with it being a G80, but he says most of them were. He's gonna open the cover and take a look just for my piece of mind, but I'll likely go for it if he says it looks ok in there.

 

They are very easy to test if installed in an axle - just grab one wheel and spin it real quick (while someone holds the other side still) - Should lock and force the torque to the opposite side. If your wheel just spins and spins... your either not spinning it fast enough... or its broke.

 

Local wrecker that I've dealt with for years has the exact same rear end with a G80 (grrrr) and want's $400 for it complete. Swears it's a good rear end because he personally drove the truck. Im a little leary with it being a G80, but he says most of them were. He's gonna open the cover and take a look just for my piece of mind, but I'll likely go for it if he says it looks ok in there.

Go for it. There are hundreds of thousands of trouble free G80 equipped rear differentials running the roads every day.
The G80 is generally problem free unless abused.

 

The G80 is generally problem free unless abused.

Is there a definition for abuse of a G80? I have an open differential and want a limited slip but because of their weakness I'll be spedning more for something that does not result in destruction with normal or heavy use. By using a swing weight operation it will eventually end up destroyed with normal use but might just take longer on vehicles that don't see snow/ice which allow the tire which looses traction to spin up quickly before the differential can lock-up.

 

The problem with the G80 is not really snow or mud... It's when you use it on high traction surface, like trying to do a burnout.

I live where we have snow on the ground for 5 months, and never seen a destroyed G80 here...
It's designed to be used on low traction surface with gentle power to engage it...

 

^^^Nailed it.

 

Installed the replacement rear end this weekend and the truck is now back up and running perfectly. Had a good look inside the new rear end when I pulled the cover off and it looks very good, no obvious wear or anything, so we shall see how this one does. Thanks to all who contributed!

 

The G80 is generally problem free unless abused.

Is there a definition for abuse of a G80? I have an open differential and want a limited slip but because of their weakness I'll be spedning more for something that does not result in destruction with normal or heavy use.

The G80, particularly the clutches, doesn't like heat. At curb you can split-mu WOT launches until you run out of gas before it will fail. As long as you keep the fluid moving around and circulating around the clutches. Axle lube has a finite temperature it can reach; but the clutches generate [friction] heat with each engagement and need to be cooled. (not after each engagement - but somewhat periodically)

"But I have a truck, I do truck stuff, with shit in the bed." - No problem - weigh just increases traction, that increases friction - the G80 will handle it - again - just need to make sure the clutches get cool.

You asked for abuse - don't do burn out after burn out tied up to a trailer, for hours on end and you'll be fine. Normal to heavy use will be fine and a G80 will last a long time. The G80 has fuse disk, that if does happen to fail, reverts the diff to open. Doesn't strand you on the side of the road having to get a tow truck and an immediate repair cost. You can drive on it indefinitely if need be.

By using a swing weight operation it will eventually end up destroyed with normal use but might just take longer on vehicles that don't see snow/ice which allow the tire which looses traction to spin up quickly before the differential can lock-up..

Sure you can "grenade" the reaction block or cam-plate - but that usually has a requirement of the truck being airborne, or some other 'hold my beer moment'...

In a truck - I'd stand by it over a limited slip.