: Question on rear end fluid additive

07-20-11, 01:36 PM
I'm prepping my bone stock 09 manual trans daily driver sedan with 30K miles for a two-day HPDE next weekend here in So CA. I'm doing both trans and rear end fluid replacements, and wanted to confirm what factory additive I need the dealer to include for the rear. Also flushing brake system during a braided brake line replacement and replacing with a high temp fluid. Any one brake fluid significantly better than the other? OEM pads are still over 50% which should last through the weekend, bumping up the pressures on the Hankooks, installing new Gates green belts, cooling system refresh, oil change, new K&N air filter installed, anything else I've overlooked?

Thanks in advance for your enlightened replies.

07-20-11, 01:42 PM
I changed my rear fluid and the spec doesnt call for the additive, but my rear made all kinds of noise until we added it back in.

for brake fluid, I flushed mine with the super blue and it worked great.

07-20-11, 02:19 PM
Evil/anyone, do you have a name/part # for that additive?

07-20-11, 02:21 PM
it was standard GM Limited Slip additive....same stuff I have used for years in all my my performance cars.

07-21-11, 12:19 AM
Yeah, go with a different color so it's easy to see. I also used the blue.

07-21-11, 12:23 AM
I use Amsoil Severe Gear and tossed in their additive. Works like a champ.

07-21-11, 12:45 AM
Rear Differential Limited slip additive

GM part number US: 1052358
GM part Number Canada: 992694

Rear Differential Lubricant: 75W90 Axle Lubricant (synthetic)
US part Number: 89021677
Canada: 89021678

This is for a 2011 CTS-V

07-26-11, 11:28 PM
I use Amsoil Severe Gear and their additive for my diff. I boiled ATE fluid in my '04 V so I've run Motul 600 fluid in that and my '09 ever since...