Limited Slip Additive
Drifting
Joined: Aug 2009
Posts: 1,346
Likes: 160
From: new iberia la
No, just Not wasting my time thinking the new oil will have enough for old clutches...and I won t have to put it back on the lift and I won t need to drain some oil out to make room for more friction modifier when the chatter doesn t stop . But you enjoy ...
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
You don't need friction Modifier with the newer synthetic gear oils like Mobil 1, Valvoline, Royal Purple etc..NOT needed. Mobil 1 75W-90 now for 25 years with no friction modifier and the diff behaves perfectly....The only service I have performed is to change the oil every 7-8 years...
Last edited by jb78L-82; Feb 10, 2016 at 01:37 PM.
Pro
Joined: Feb 2014
Posts: 546
Likes: 7
From: Kansas
You don't need friction Modifier with the newer synthetic gear oils like Mobil 1, Valvoline, Royal Purple etc..NOT needed. Mobil 1 75W-90 now for 25 years with no friction modifier and the diff behaves perfectly....The only service I have performed is to change the oil every 7-8 years...
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Verdad Gallardo
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you use non-synthetic gear oil, one bottle of additive is needed. But, I wouldn't put new additive in "old" oil. Suck out the old stuff and add fresh oil and additive. (You need 1-1/2 bottles of gear oil. Empty diffy; put in one bottle oil; put in the additive; fill to plug hole with some of the second bottle; install plug.)
But, I also suggest that you put synthetic gear oil in the diffy WITHOUT the additive. MUCH better lubricitiy and reduced frictional losses.
But, I also suggest that you put synthetic gear oil in the diffy WITHOUT the additive. MUCH better lubricitiy and reduced frictional losses.
1st Gear
Joined: Feb 2016
Posts: 1
Likes: 0
Run what you want, but our old (and new) Eaton Posi's are designed for use with conventional lube with the 4 oz. bottle of GM friction modifier. Eaton recommends against synthetics. The folks at Eaton say conventional gear lube "performs best" vs. synthetics.
More here:
http://www.eaton.com/Eaton/ProductsS...ials/index.htm
No doubt synthetics have their applications but not here. Being more slippery, synthetics could reduce posi-traction effectiveness.
More here:
http://www.eaton.com/Eaton/ProductsS...ials/index.htm
No doubt synthetics have their applications but not here. Being more slippery, synthetics could reduce posi-traction effectiveness.
Melting Slicks
Joined: Mar 2008
Posts: 2,989
Likes: 198
From: Meriden CT
Run what you want, but our old (and new) Eaton Posi's are designed for use with conventional lube with the 4 oz. bottle of GM friction modifier. Eaton recommends against synthetics. The folks at Eaton say conventional gear lube "performs best" vs. synthetics.
More here:
http://www.eaton.com/Eaton/ProductsS...ials/index.htm
No doubt synthetics have their applications but not here. Being more slippery, synthetics could reduce posi-traction effectiveness.
More here:
http://www.eaton.com/Eaton/ProductsS...ials/index.htm
No doubt synthetics have their applications but not here. Being more slippery, synthetics could reduce posi-traction effectiveness.
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
Le Mans Master
Joined: Oct 2007
Posts: 9,700
Likes: 3,469
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
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Many of the Eaton locking type differentials use a mechanical lock instead of clutches. Due to this, you NEED friction for the interferance locks to lock. Friction modifier and synthetics are too slippery. Standard posi diffs with clutches need the modified and perform better with synthetics.
Last edited by Kubs; Feb 11, 2016 at 09:13 PM.
Racer
Joined: Oct 2010
Posts: 308
Likes: 43
From: Suffield CT
I ended up needing 2 bottles of friction modifier, on top of running synthetic. Just had a slight whine and chatter on tight turns even after the first bottle, but now it's nice and quiet and still grabs like it should.
Last edited by a71vette; Feb 11, 2016 at 09:27 PM.