I am planning on draining my diff oil and pulling the cover off. Bought a new gasket and was told to put it on dry. What is the torque setting on the bolts? Also I read that the Eaton G-80 takes GL-5 75-90w synthetic without any friction modifyers added. I have Royal Purple Max-Gear synthetic, it contains limited slip additives (friction modifiers). Mobil 1 gear oil also has this additive. I do not know what the GM grape juice has. Redline has a gear oil without any friction modifiers added. What would be your suggestion on gear oil?:rolleyes:

On the GM HD trucks the rear gasket should be reusable. It's a special rubber on steel unit.

Torque is around 20 lbs

I think the G-80 needs friction modifiers. It has clutches. I used the Redline in my GMC.

http://www.getdieselpower.com/my01dmax_files/mag-hytec/images/DSCN1161.jpg

http://www.getdieselpower.com/my01dmax_files/mag-hytec/images/DSCN1163.jpg

I was also getting ready to change mine but I have a couple of ??...first, Isn't there a drain plug on the bottom of the diff. to drain out the fluid? and, second, Should drain it out when the fluid is cold or, should I run the truck a little bit to warm up the fluid before removing?

JLew:D

I was also getting ready to change mine but I have a couple of ??...first, Isn't there a drain plug on the bottom of the diff. to drain out the fluid? and, second, Should drain it out when the fluid is cold or, should I run the truck a little bit to warm up the fluid before removing?

JLew:D

Yes there is a drain plug. I should have mentioned that. But I prefer to remove the cover to wipe out the insides. It's simple enough and you don't need a gasket. You get to see all those frail little parts and wipe out all the damage ;)
Seriously those internals hold up pretty well. They just can't handle major abuse.

I think there is a magnet on the inside of the cover. You want to wipe off all the filings.

Thanks a bunch for the reply. If the gasket looks good I think I will reuse it. Reading a little deeper into the G-80, you are right on the oil also. Thanks again.

The G80 does NOT require friction modifiers.. This is not a clutch pack limited slip. It's a governor controlled locker.

The drain plug is the magnet. Mine was anyway.

Half right JJ. It does have a clutch pack that is locked or unlocked. Check out this link.

http://www.traction.eaton.com/prod2.htm

Later! Frank

Nice thanks for finding that that was pretty neat. Mine is a little slow to kick in some times so I would say that I can notice sometimes when it does or doesn't kick in right away and why I won't lock up when I fly around a corner. That kinda of sucks but for most it is most likely safer that way.

I thought the needed additive was included with the GL-5 and that is why they do want you to add more. That is what I had learned through rebuilding the 10 bolts G80.

I thought the needed additive was included with the GL-5 and that is why they do want you to add more. That is what I had learned through rebuilding the 10 bolts G80.


i think that is correct.