i have been reading around and after i looked at my RPO codes, i found out that i have a g80 rear end...sweet! i am wondering if there is an easy way to test to see if my g80 is working the way they describe it should work. any thoughts?

 

do some muddin =]

 

It's very easy. Jack up the back end so both wheels are off the ground. Place the vehicle in park. Give one of the rear wheels a quick spin and watch the other. You will feel it catch and then the other wheel will turn in the same direction. If you just turn it slowly it will just act like a standard open diff.

I need to get mine swapped from my Sonoma to my Blazer before it gets winter time

 

It should not be that easy to spin a G80 diff. All of the ones I have ever worked were quite difficult to get them to spin when the transmission was in park. They actually have a light preload to the clutch pack inside the diff which can make it difficult to get the diff to act like an open diff by hand.

 

In my sonoma on dry pavement it will leave a couple of nice black marks




If you have a locking diff and have it in 4x4 mode is that considered a 3 wheel drive?? Since the front is an open diff??

 

well from what i understand of the g80, it acts like an open diff until it senses one well turning less than 100rpm to the other. i do know that if i brake stand my blazer it burns both tires, but i do not think that the axle is completely locked together, more like an lsd than a true locker. with the g80, i should be able to have one tire completely off the ground and the other still on the ground and when i put it in drive, the tire off the ground should spin just for a few moments before the locker kicks in and drives the blazer forward..right? does the g80 make any clicking noises when the locker is engaging?

 

Oopsey

 

Yes, there is a good "clunk" you can hear if you are listening for it. If you think yours has problems engaging, change your diff fluid for some high quality synthetic oil. I switched mine out to Royal Purple and it engages better now. Looky here:

http://www.youtube.com/watch?v=tTGZOJQQBeE

http://www.youtube.com/watch?v=p8nAbg5suFw

http://www.youtube.com/watch?v=rGlacQlBGcQ

 

You are correct, however, there is a preload to the clutches which would offer up quite a bit of resistance to turning it by hand as I have said. If it spins over really easy, then the clutches are likely worn pretty hard. This preload is not enough to be a true LSD until it locks since your truck is capable of applying a lot more power to the axle than you are by hand.