I think my dealer is drinking differential fluid...

[strobhen]

I call them up to ask if my car needs the GM additive. This is a service advisor mind you.

"No, you need to use our gear mesh fluid, its real expensive. Don't put the wrong fluid in, it will ruin it, come down here and let us take car of it. Its 129 bucks."

:rolleyes:

Damn, they are making over 100 bucks on labor to take off a cover and put it back on.

At any rate, I'd like to know a few things:
1. Do I need to use the GM additive. I'm hearing its optional since I have the torsen. If I can use it, I probably will.
2. I'm thinking this liquid gold gear mesh fluid is bs, please confirm.
3. I should use 75w-90 gear fluid, correct?

Just want to confirm some stuff and give a warning to others out there about stupid dealerships.

[Dominic]

You do not need the GM additive, but you can use it. I have it in mine currently due to a TSB posted about how it quieted torsen howl in hard cornering... so the GM dealer tossed some in to warrant the torsen I had them install. If however I change it in the future I will not buy the additive... I will likely run mobil1 or valvoline 75W-90 (Currently running valvoline, very satisfied).

The gear mesh fluid is not bad, but is not synthetic, and is not worth the cost. Its not a hard operation to do yourself, especially if you have a cover with a drain bolt on it or an electric pump you can use to keep from unbolting the cover. Unbolting the cover is also easy, but can get messy. Get some rhino ramps, back it up, and do it [img]smile.gif[/img] you'll need 2 qts.

75W-90 is fine back there... Even 80W-90 is fine.

[strobhen]

Thankye Dominic

I will go down & grab the additive. A few bucks more for a quiet differential is worth it. Plus I have read on a couple ls1 boards theories that it may help wear & tear just a tad.

I plan to do it by unbolting the cover, have a nice big oil pan. [img]smile.gif[/img] Even a brand new torque wrench (going to do transmission fluid soon too).