What type of gear oil in the rear diff? So confusing

[newbie78]

I have a G80 rpo code on my 1997 tahoe and i read that it's a locking differential and you don't use gear oil with limited slip additive.

Then I look up the rpo code and it says a G80 is a limited slip differential ??

I just bought Valvoline 80w90 that has a little label on the front that says limited slip.

http://shop.advanceautoparts.com/p/valvoline-high-performance-80w-90-gear-oil-vv831/7070003-P?searchTerm=gear+oil

I read in the owners manual it says 80w90 GL5 rated gear oil.

Will the valvoline stuff i got work or do i need to take it back? thanks

 

[SunlitComet]

you can use that but an additive in not needed for a g80 govbomb.

 

[newbie78]

you can use that but an additive in not needed for a g80 govbomb.

I'm reading that using gear oil with limited slip additive can damage the diff. It is a locker not a limited slip.

 

[SunlitComet]

not heard it stated like that.

 

[MarkD51]

Not aware of GM ever placing a "locker" type from the factory. When I say locker, I mean something like a real locker, like a Detroit Locker. Otherwise as far as I know, these are what's referred to as "Limited Slip".

Most factory limited slip differentials offer little more than open rears. Example, jack one side of the truck up, that wheel will be spinning, while the other down on the ground doesn't have the muscle to pull the truck off the jack. This same thing happens in snow-ice, even in 4x4 mode, one wheel in front, and one wheel in back doing the work.

From just a few thousand on till now, I've been using Mobil 1 full synthetic 75-90w no issues.

I feel full synth such as Mobil 1 will hold advantages in that synthetics offer better cold pourability, meaning in extreme cold the lube is doing its job sooner, before the axles are fully warmed up. and also are claimed better hi heat protection.
Mark

 

[SunlitComet]

mobil really just makes some superior s***. nuff said.