Rear Differential Lube?
 

I'm planning to change out the lube in my rear differential with Mobil 1 75w-90 LS. I looked this up online and found that it is $9 a quart. I checked with the dealership for the price of the GM lube and additive and it cost $55. Just wanted to make sure I was getting the right Mobil 1 lube. The large difference in price frightened me. :confused0068:
http://www.oreillyauto.com/site/c/de...2370&ppt=C1985

Will someone please take a look and confirm I have the correct Mobil 1 Lube?

That's the stuff I used 10k miles ago. :thumbsup: No issues with my diff. I did some low speed donuts and "S" turns after I swapped the fluid.

You can get the 'lube' additive at autozone for pretty cheap. No need to buy the expensive dealer stuff. Also of note, the Mobile 1 LS fluid says it has friction modifier in it but if you dont add the extra stuff the gears make bad noises.

How much additive did you add to the Mobil?

I didn't buy the additive. The Mobil 1 LS is supposed to have the additive already. No noises from my diff. If you want to add it, check your owner's manual. It list how much should be put in.

Does RP affect the warranty?

I strongly recommend using Mobil 1 75W90 gear oil because it is
endorsed and highly recommended by GM engineering.
Mobil 1 75W90 gear oil is a excellent choice to use in my opinion.

And you still need the additive.

Although I usually use Mobil 1 anyways the endorsements are paid for and don't really mean anything. I use that or RP depending on what I can find at a decent price.

I disagree with you it's not a money game like you think
GM engineering did alot of researching and testing before
they knew that Mobil 1 products was the best oils to use
in all GM vehicles.Having talked to a GM engineer before
he gave me his insight and said Mobil 1 was the best choice
for all GM vehicles I belive him over anyone on this forum.
Also yes I forgot to say definitley use the additive with
the Mobil 1 75W90 gear oil.

The brand of oil the companies use for the first oil change won't have a major impact on an engines life. Every part the car companies use have to undergo testing to verify it meets standards and its definitely a rigorous process. But it doesn't mean its the only one that meets those standards. The marketing and hype that happens afterwards is all $$$$ as its a mutually beneficial relationship. When it comes to mass production everything is a numbers game as every penny impacts their profit margins.

I thought we were talking about gear lube, and whereas GM chooses to use Mobil 1 as their factory fill for engines, they don't use it for their differentials.

You can buy the GM lube at auto stores under the DELCO label for about $15 a quart.

Edit: I used Mobil 1 in an Auburn 4.10 locker that failed a few years back. Mobil 1 in the crankcase is great. In the differential...not so much.

Were you still using the weak 10 bolt rear end?
There is your answer then.
From all the independent tests I have seen Mobil 1 synthetic gear oil is
one of the best brands of gear oils you can use aspecially in a Camaro.

I have mobil1 in the rear and love it. I added a couple ounces of the LS modifier with it just incase. Did about 10 figure eights to break it in and it's WAY better than stock. Nice n' smooth. I also have mobil1 in the tranny, which helps too.