Synthetic or not?
Thread Starter
Staging Lane
Joined: Jan 2009
Posts: 83
Likes: 2
From: CO
Synthetic or not? I want to change my diff fluid I think it is the original 12yr old fluid, granted only 50K on it but I would like to upgrade to synthetic. I have done a search and have found mixed results about running synthetic fluid, so I am undecided on what route to take? I know you need to add the GM friction adifer to the diff with the fluid and from what I gathered redline seems the way to go. I just want to get another opinion before I go ahead and change the fluid. I currently have a quite non leaking rear end and would like to keep it that way and if synthetic is going to mess that up I’ll stick with the regular stuff. Thanks
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
What year is your car? 99-02 usually don't need the additive bc they have a torsen posi thats all gear driven. Syn fluid has the additive already in it.
if u got 98 with auburn, then STAY AWAY FROM SYNTHETIC , using valvoline 80w90 with GM/Ford friction modify ( I find out that ford stuff is better and its like 5 dollar cheaper then gm stuff ). Change every 2 year or 30k miles.
Right now im using Lucas 80w90 that already have friction mod in it, add ford friction, cool and quiet ^^.
Right now im using Lucas 80w90 that already have friction mod in it, add ford friction, cool and quiet ^^.
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Verdad Gallardo IIRC it's because it has clutches as opposed to the Torsen which is "just" gears.
My eaton posi 19599-010 in my 87 takes dino oil as well. It too is a clutch style LSD.
http://www.summitracing.com/parts/ETN-19599-010/
I've run that fancy lakewood stuff, and basic valvoline.
http://www.summitracing.com/parts/LAK-32970/
My eaton posi 19599-010 in my 87 takes dino oil as well. It too is a clutch style LSD.
http://www.summitracing.com/parts/ETN-19599-010/
I've run that fancy lakewood stuff, and basic valvoline.
http://www.summitracing.com/parts/LAK-32970/
Banned
Joined: Oct 2009
Posts: 992
Likes: 1
Auburn uses a cone clutch that isn't synthetic friendly. I installed a brand new Auburn and tried using Mobil 1 synthetic gear oil, It wasn't good. The cone clutches didn't like it and I ended with a rear full of metal from the clutches in 2k miles. I went back to a Torsen carrier, car handles so much better.
TECH Apprentice
Joined: Jan 2004
Posts: 392
Likes: 0
I have an '01 Z28 and am thinking about changing my diff fluid this weekend. I still have the stock 10 bolt and won't upgrade my rear for years (other things to do first). What fluid and should I use a gasket or RTV?
EDIT: Let me rephrase - I know what fluid to use, I just don't know if I need any additive or not.
EDIT: Let me rephrase - I know what fluid to use, I just don't know if I need any additive or not.
Last edited by Darth Cypher; Oct 8, 2011 at 03:22 PM.