1990 K5 GM Codes in Glovebox Question
 

I'm Guessing that G80 in a 1990 K5 does not equal locker like the newer trucks right?

Sure does.

Really? I was skeptical....

How do I know for sure if its there or previous owners took it out?

Im about to pull the cover off, is there a way to actually see the difference? or something else I can do?

If you only see 4 spider gears in the center of the diff and not much else, it's an open diff. If you see weights, clutches, etc, then it's a G80.

or a bunch of broken parts and teeth missing off the little sliding pieces in there then you have a g80 :)

i swear i dont think i have ever opened a axle on a k5 where that thing wasnt stripped up or broken.

Whew, forgot what the diff smell does to a garage... took the cover off, this is what i saw... no grenade went off in there...

G80 or other? LSD mebbie? Im new at this...


http://forwarding.dyndns.org:8082/k5.../WP_000108.jpg

That's a G80.

So Im guessing based on the other poster, that the G80 isnt as great as I thought... I dont plan on rock crawling in this thing just light offroading... so I hope it does ok and doesnt fall apart.

Thx for the info BTW!

Also all the documentation points to my year being a posi, is that what a posi looks like, or thats definatley a G80 locker... Im not trying to argue, just wonder if someone put that in there after the factory or something... I have no history of my vehicle.

That is definitely a G80. A posi would have a bunch of springs in the middle. The picture you posted shows the governor assembly which is what triggers the axle lock when wheel slip is detected. Just below that is the weight which disables the locking action over ~30mph.

The Eaton G80 differential isn't all that bad so long as you stay reasonable and understand how it operates. Given that it locks up on detection of wheel spin, you want to give it a chance to lock in before you put a lot of power to it. If you are in the gas hard and one wheel starts to spin, especially with larger tires, the locking action will shock the diff and bad things can happen. Then there is the point to be made that there are clutches inside that once they wear out, you will essentially have an open differential.

Some have experienced spectacular destruction of their G80 while others have had very good luck with them. I am in the latter category. We have had G80's in the last few farm trucks on my father's farm and these trucks have been royally abused with no diff failures.