Rear end fluid question?
Melting Slicks
Joined: Nov 2004
Posts: 2,275
Likes: 5
From: Lake Oswego, Near Portland Oregon
I just went through a differential fluid change due to chattering/grunting Limited Slip clutch plates. I ended up using Red Line 75/90 that already has the special additive for the clutches in it....there is also the same weight from Red Line that does NOT have the additive 75/90NS, but you don't want that one....Also good according to many posters here is Amsoil product, but I do not have that available off the shelf locally, and have never used any of their products....If you use a 'generic' 75/90 gear oil, you MUST get the special additive for the Limi-slip chutch plates and make sure you get the correct amount in the differential along with the oil. GM stealerships sell the additive, and some oil companies also sell it seperately....I found the Red Line the easy way to go....fantastic products and ready to use.
Last edited by FiberglassFan; Jul 5, 2010 at 02:15 AM.
Pro
Joined: Mar 2004
Posts: 653
Likes: 0
You want 75W-90 or thicker, depending on how you use the car.
FiberglassFan described the requirements perfectly (and she scored a recent win in this area) so give her post a read and go shopping.
I've also had great results w/ RedLine gear oil over the years and strongly recommend it. Nothing bad to say about Mobil-1 75W-90-LS either, and most auto parts chain stores carry it.
Thread Starter
Pro
Joined: Jul 2008
Posts: 564
Likes: 1
From: Moyock NC
I just went through a differential fluid change due to chattering/grunting Limited Slip clutch plates. I ended up using Red Line 75/90 that already has the special additive for the clutches in it....there is also the same weight from Red Line that does NOT have the additive 75/90NS, but you don't want that one....Also good according to many posters here is Amsoil product, but I do not have that available off the shelf locally, and have never used any of their products....If you use a 'generic' 75/90 gear oil, you MUST get the special additive for the Limi-slip chutch plates and make sure you get the correct amount in the differential along with the oil. GM stealerships sell the additive, and some oil companies also sell it seperately....I found the Red Line the easy way to go....fantastic products and ready to use.
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Safety Car
Joined: Aug 2007
Posts: 4,506
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From: This is not a Song, It's an Outburst: Or, The Establishment Blues; Sixto Diaz Rodriguez
Just changed my differential gear oil Wednesday because of "chattering." Went with Amsoil Severe Gear, 75/90W and added a tube of slip additive, and so far chattering is gone.
