Repair or replace G80?

Winter is here in full force in Alaska, and so I've been working on my truck, taking care of maintenance items that have gone too far.

After dropping the cover in my rear differential, I notice that the small gear mechanism for the Eaton G80 has sheared a number of splines.

This leaves me in a bit of a quandary- on the one hand, I'm a firm believer in upgrading failed parts with stronger ones; on the other, I'm not made of money.

My question is this- is the G80 really as weak as it is made out to be?

I'm considering an Eaton Truetrac to replace the G80, but at $450, it's a bit pricey.

My second question is whether there is a boneyard center section that would be an upgrade. (my truck has a 14 bolt semi-float rear, with 6 lug axles, drum brakes and 3.73 gears)

my opinion only.....no, it's not as weak as "everybody" says. especially in the larger axles. when you hear of these "it's crap" statements it's usually because someone is taking it beyond it's intended purpose....ie: large heavy tires. under stockish street use there really shouldn't be any problem. my general rule is if a stock part fails upgrade it......but if it's a money thing i could
ld see myself rebuilding it.......i subscribe to the "buy once, cry once" theory......right now i can't afford to pay attention so that goes out the window. when i am ready to get a semi-floatin 14 bolt for my truck, if it has the G80 i'll just bolt it in.....though i'd sure want a selectable unit.

How long did the stock one last? My G80 is pushing 23 years old and 200k+ miles. If it were mine, I’d rebuild it.

I'd forget about the G80 simply because of the design if it were my truck. I agree with @shovelbill in terms of reliability, I just hate the way they operate. I wouldn't put any time or money into a "locker" that turns into an open differential over 20MPH.

As to how long this one lasted, I have no idea. I would assume that I would have heard or felt the differential go, but I never did, so I'm assuming that it failed prior to my owning the truck. If that is the case, I've driven it like this for almost 20k miles...

My understanding (and believe me, I'm no differential guru) is that the G80 is at its worst when encountering roads that are a combination of icy & dry- get one tire on ice, and another on dry pavement and you've a recipe for the failure indicated in my original post. If this is true, I *really* do not want to keep the G80- Alaskan roads are notoriously icy.

I don't think G80s are considered junk on account of how strong they are. It has more to do with the way that they behave. They designed it (for reasons that I have yet to fathom) to unlock at speeds over 20mph.

I was apparently intoxicated when I found a TrueTrac for my truck at $450. They're actually about $750 for the 14 bolt... That takes it squarely out of my price range.


Is there a better differential that can be sourced in a junkyard?

I have 2 G80s 1 220K miles works fine always locks on dirt, ice, until this summer I got into some soft grassy ground to the point of wheel hop. It still works but made a crunching noise that I am sure something slipped. I have tested it on dirt and will stay locked till 20 mph. The other is 56K miles no problems works fine. I had another truck I put a Auburn locker in that was rock solid and wheel hopped till the engine moved so far it cut the upper radiator hose. They are about $400-450 @ summit racing.

So, the price of a junkyard rear axle was only $300, came with everything but the drums and shoes. Got it cleaned up, replaced the axle seals and put on a fresh coat of paint. I'll be taking out my old axle, and over the course of the next year or so, will rebuild it with a TrueTrac differential. This gets me on the road now, and gives me an axle to rebuild. Win/Win.

Thanks all for the advice!