buckmeister2

Folks,

I am going to change the rear diff fluid, and wanted to know if there are any correct alternatives to the GM product. Also, I see differences in the listed capacity for the LS3...some say 2.1 quarts will do the job, some say 4 quarts. What is the correct amount?

(added after realizing my first idiot move of the day)....car is a 2008 base A6.

Thanks to all!

Jim

jft69z

It helps if you list what year and model...

rkj427

helps to know year and model.......

and just a FYI alternative lube may not contain same chemicals mixed to optimize differential clutch plate performance as the OEM lube.......may lead to chatter or noise concerns.....

buckmeister2

Thanks, JFT & RKJ...added above, car is 08 base A6...

jft69z

2008 base model calls for approx. 2.12 qts of Dex LS gear oil.

Absolutevil

I used Mobil 1 LS formula and have put many miles on the car since and still have no noise or issues.

Curt D

GM stuff works great. 2 qts will do ya. I bought 3 and Didn't use it. Just fill it till it runs back out of the fill hole.

buckmeister2

How many miles ago did you put it in?

I went to mobil.com and read the specs, and they say it has LS additive built in. I wonder if it is possible the Mobil 1 LS 75w-90 is essentially the same as Dexron LS?

irok

just add the correct GM Dexron oil and you wont have to wonder or have any issues.p/n 88862624

Absolutevil

I've probably put almost 10k on since I changed fluid to the Mobil LS formula. I'd use it again.

red430

I used the Mobil LS in my Escalade, works great. Use Redlinei n diff. Of my 08 Vette never a problem with Redline all the additives are in it, no chatter.

Cherokee Nation

I had the dealer change out my with the GM Dexron over 70,000 miles ago on my 08 and no problems since..So why would anyone use any other oil!

Racer

. Sorry, I had the famous rearend chatter and I did the recommended GM procedure and the above mentioned products and still had the rearend chatter. I tried the Amsoil and NO MORE CHATTER. Three years and counting. Your results may vary.

Beef97

Just did mine today and only drove it around the block but didn't hear any noise at all. Amsoil severe gear

HOXXOH

'08 A6 here with 141K miles. No chatter and more importantly the posi-traction works correctly. Equal tire spin on burnouts and equal traction on the launch. Dexron LS pn 88862624 used from the factory and two subsequent changes.

avoZ28

My local guy is doing my complete tune up tomorrow and is recommending redline fluid for the differential and the manual transmission. I figured he knows more then me since I see vettes ferraris and lambos in his shop often. He says he uses redline fluid for all of them and they work great. He mentioned there's an additive for the differential as well. From what I'm reading here I'm not sure if I should let him go ahead or maybe buy the GM fluid and take it to him?

HOXXOH

GM's fluid comes with the precise mixture ratio of lubrication and friction modifer that has been tested for hundreds of thousands of miles by highly qualified people. GM used to sell it as two-parts to be mixed by the mechanic, who apparently couldn't always get it right and caused the change to pre-mixed.
What expectations do you have about the guy who wants to sell his product and his ability to mix an unknown additive to a special lubricant in the right proportions? Because he also services exotic cars, doesn't mean he is a qualified engineer to test and evaluate fluids in C6 Vettes.

BTW, check your owner's manual for fluid change intervals. If you find no mileage recommendation, then 150K miles is the default.

HOXXOH

If you research deep enough, you'll find that Mobil is the source for the Delco Dexron LS and GM Dexos brand oil (not just the Dexos spec). However, all manufacturers who put a label on a product other than their own, produce the product to their customer's specifications. Sometimes those specifications are identical, but usually they are not, in an effort to protect their own product.

avoZ28

Thanks for the Info, I'll head to GM and pick up the fluid

Ward Cleaver

Because the rear differential lubricant (and other products such as oil filters, etc.) that you'll get at your local dealership is "good enough," but there are some other products that are superior to it.

Some folks are okay with "good enough," but some folks want something better than just "good enough."

Motul 300 LS 75w90 fully synthetic gear oil is an example of a rear differential lubricant for the C6 that is superior to the "good enough" lubricant that you'll get at your dealership.


Regards,
-Ward