mcalus

iTrader: (14)

I did do a search and only came up with aftermarket rears.

I just replaced the outer right axle bearing and a new used axle.

What type of gear oil should I put in it?

Car is a 99 Z28, M6, Stock 10 bolt, 3:42's, its my DD.

Thank you!!

Adam2001WS6

iTrader: (1)

Mobil1 75W-90 and add a bottle of the GM Rear End Additive (GM 1052358)

Never look back....

mcalus

iTrader: (14)

And I can get this at the local parts store? How many quarts? What is it all going to run me appx?

Thank you!!

Adam2001WS6

iTrader: (1)

You can get everything from a local auto parts store except the GM Rear End additive. You have to get that from a GM dealer (or maybe order online, but I've always just popped into the dealer).

GM Additive - $10.40
Felpro Rear End gasket - $5.14
2 qts. Mobil1 75w-90 - $19.98
Brakleen (to clean off the cover) - $2.79

With tax... Less than $40

Of course that was with the prices that my local auto parts store charged and all, but you get the idea.

Good luck fellow LS1 owner!

- Adam

mcalus

iTrader: (14)

okay, thanks! I already have the brake fluid, and new cover gasket.

Thanks again!

Anyone else have any suggestions on fluid?

stburgpete

You can pick up the additive at autozone they have it. Just got some myself.

Adam2001WS6

iTrader: (1)

Brake fluid?

You mean, Gear oil?

mcalus

iTrader: (14)

haha! Sorry typo ... Brake cleaner haha

Adam2001WS6

iTrader: (1)

Ahhh... good deal. Well if you can pick up the additive from a parts store than go for it. Just make sure it's the real GM stuff... I have never seen it in a random chain auto parts store, so be weary... Make sure you get the right stuff for GM rear ends

LS14EVR

iTrader: (3)

What if I have the SS auburn limited slip? I'm assuming this same or similar auburn rear limited slip gets put into other non-GM vehicles so not everyone is using GM additive.
Also, twice now I've seen people saying to buy gasket, but when I asked the other day, most everyone said just use RTV silicone and be done.

stburgpete

Yes autozone sells the additive and it states on the tube (GM 1052358)

01ssreda4

iTrader: (96)

Auburn=additive needed
Torsen=no addtive bc there are no clutches in it.

Putting additive in a Torsen is a waste of money and just plain silly. If you have a torsen, buy cheap **** 75/90 gear oil and you're golden.

fleetmgr

I'd put in a 75w-140 gear oil. The higher viscosity index means it'll deal with heat a much better, as in not suffer from hi temp viscosity breakdown.
I can't imagine why anybody would recommend "cheap **** gear oil". If you wouldn't do such a thing to your engine, why would you do it to your rear end gears and bearings that see higher loads than your engine ever will?

hlaalu

iTrader: (3)

I use 75w90,

to answer your gasket question, put a bead of rtv on the outside of the rear end housing, lightly press on your $3 gasket, then put a bead of rtv on rear end cover, press it on the gasket and start tightening the bolts evenly. I've never had a leak doing it this way.

LS14EVR

iTrader: (3)

I know you only need additive when there are clutches. My question was actually, doesn't someone else make an additive besides GM since this is not a GM unit, it's an auburn unit. I know GM additive will work but just asking. Sorry, not an expert on rearends. Thanks for the info on gasket. That's actually what I usually do on most gaskets, or none at all with just gasket, but I like the added insurance.

01ssreda4

iTrader: (96)

Yes Auburn makes its own additive. It comes when you purchase a new posi unit. I have seen bottles of it for sale on ebay, but other then that I dont know where you would get it.

To fleet manager, following normal services intervals, any gear oil you find on the shelf with be sufficient. Hence my recommendation of the cheap ****, thats what the rear end is designed to run.

hlaalu

iTrader: (3)

ford also has an additive. actually autozone has a generic additive but people still complain about noise when they use it.

fleetmgr

Using that logic, it makes perfect sense to run the absolute cheapest re-refined house brand motor oil you can buy as long as it has the API star and is the correct viscosity.
As the point contact loading on a single gear tooth can reach 1 million psi under the right circumstances, and cheap oils are MUCH more prone to shear breakdown than good ones are due to their increased additive contents, I'd use the good stuff here too. You've got a car that you spent thousands to buy, and in some cases have spent additional thousands on with upgrades. Many have $3 grand or so just in the rear end. Seems like cheaping out on the oil you put in that rear end is a really serious case of being penny wise and pound foolish. We're talking what, maybe a $50-$60 dollar difference to better protect your investment.

LS14EVR

iTrader: (3)

Thanks for input.

01ssreda4

iTrader: (96)

I have seen rear ends swapped to expensive syn oil and spit bearings out after a few hard launches within a week. I have also seen high mileage rear ends take abuse and only have cheap gear oil in them. Fool someone else with point contact loading jibberish.