Does the GM G80 need LS fluid?

The 10.5" Corporate carrier is fully enclosed & you can't see the Gov-Loc guts.....You can see them on the 11.5" AAM though.
Hi Mr. Clinebarger. I just saw this on E bay and noticed it looked a lot like what is sitting in my carrier of my 2008 3/4 ton Suburban. It’s definitely conical in shape and does not look like the photos of a normal G-80 locker. Any thoughts on this.? I’ve owned my Burb since new and it’s the original diff. I’ve included pics of my diff with the cover off. Thanks.

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G80 is simply the RPO (Regular Production Option) for any type of non-open differential. It is been used since the 70's at least. IMO the confusion comes in when someone decided to just call it a G80.

So unless you KNOW for a fact there was only one kind of LSD/Locking diff used in that year and model (and I understand that may be the case with the OP) all G80 on the SPID tells you is that it isn't supposed to be a one wheel peel....
Yes, here is something from Sierra Gear showing G-80 meaning “ not open diff “. It’s true enough the Eaton M Gov Lock has taken on the name G-80 but in the case of my 2008 3/4 Suburban, it has a factory installed Posi-traction but the glove compartment sticker said G-80. I’m still trying to learn more about it.

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I did a quick check on my rear axle to check for a limited slip differential.

1. With the tires in the air, I rotated one tire in the forward direction, and the opposite tire rotated in the backwards direction.

2. I had my son hold the driver’s side rear tire stationary and I tried to turn the passenger side. It would not turn.

Looks like I have a limited slip differential but it is not a G-80 Gov Lock judging from its conical shape.
 
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Here is something about the G-80 “Gov-Loc” for GM trucks. Two photos are for 14 bolt rear ends, one is for a 14 bolt 10.5 inch ring gear and one is for a 14 bolt 11.5 inch ring gear. A third photo is a non 14 bolt version. Notice how the two versions for the 14 bolt look completely different. The 10.5” ring gear version is “conical shaped” yet the internal parts are for a “locking” assembly.

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I think this is the best example of what’s in my 3/4 ton Suburban. It’s a Posi Traction but not a Gov Lock as far as I can tell.

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I’m correcting my older post. Although labeled as a positraction, it is a G-80 locking differential. There were some other posts discussing why the 14 bolt 10.5 G-80 looks different from a 1/2 ton G-80. It’s just the way it is.
 
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