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#26 | |
Active Member
![]() Join Date: Oct 2002
Location: Ft. Myers, Fl
Posts: 1,716
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Re: Rear End Gear Oil
Quote:
I was going to use Royal Purple in my posi unit, now I know better. |
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#27 |
Senior Member
![]() Join Date: May 2003
Location: Sandown, NH
Posts: 2,820
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Re: Rear End Gear Oil
I copied this right off page 25 from Eatons Posi manual I linked from my previous post, and it clearly states either can be used, provided enough friction additive is used ! Just say-in !
Now this is out of a current manual, not a 40 yr old one ! Eaton Posi™ Quality mineral or synthetic lube with sufficient friction modifier content will ensure the smoothest operating and longest life of your Eaton Posi performance differential. Eaton recommends GM Dexron LS or Castrol Carbon Mod SAF (Synthetic Axle Fluid) for all Posi applications. If using non-“LS” gear lube, add four ounces of General Motors “Limited Slip Axle Lubricant Additive” per one-and-a-half quarts of gear lube (GM P/N 88900330/10-4003). Additional friction modifier additive may be used to reduce LSD plate “chatter,” but do not exceed eight ounces per one-and-a-half quarts of lube. Other brands of additives may be used. A friction modifier's purpose is to lower the static coefficient of friction (grabbing) within the clutch to match the dynamic friction (sliding) in an effort to reduce the effects of friction transition (stick, slip, chatter). Excessive amounts of a friction modifier can lower both friction values, resulting in reduction of bias ratio (performance) for plate-style limited-slip differentials such as the Eaton Posi. Many brand name gear lubes contain some limited-slip friction modifier in their formulation. If you use such a lube, additional friction modifier additives should be used sparingly to avoid accidental over-saturation resulting in performance loss.
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Gary 72 SWB 4x4 My 72 SWB Build http://67-72chevytrucks.com/vboard/s...d.php?t=259859 |
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#28 |
Senior Member
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
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Re: Rear End Gear Oil
no you dont if you think fitz knows what he is spouting bullcrap about
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71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY |
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#29 | |
Registered User
![]() Join Date: Jun 2014
Location: Shingle Springs, CA
Posts: 869
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Re: Rear End Gear Oil
Quote:
Just getting off shift and back on the forum. WOW...I missed a lot. |
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#30 | |
Six in a row makes it go...
![]() Join Date: Mar 2009
Location: Vacationland: Maine
Posts: 1,346
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Re: Rear End Gear Oil
Quote:
__________________
67 C20 long step resto: http://67-72chevytrucks.com/vboard/s...d.php?t=342086 66 C10 long step build: http://67-72chevytrucks.com/vboard/s...=1#post3814790 CT to Alaska in a 67 C10: http://67-72chevytrucks.com/vboard/s...d.php?t=399224 “The height of sophistication is simplicity." - Clare Boothe Luce |
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#31 |
Senior Member
![]() Join Date: May 2003
Location: Sandown, NH
Posts: 2,820
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Re: Rear End Gear Oil
Yeah some of our board members are pretty intense about what they believe is correct. Nothing wrong with that, they most likely developed their knowledge from experience, what they were taught and what worked for them. I personally have never used synthetic gear lube ( Motor oil Yes ) and I believe that is superior to conventional oil ! I have an older Eaton posi in my truck that I'm re-gearing now. I plan to used conventional 80-90w with the additive, it's worked for me so far, never had a problem with it.
The only reason I would question synthetic would be based on the material of the friction discs. Some are carbon discs, and I have no idea if synthetic is compatible with them ? Anyway, the manual says you can used either, so weigh everyone’s impute, make your choice and go with it ! Gary
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Gary 72 SWB 4x4 My 72 SWB Build http://67-72chevytrucks.com/vboard/s...d.php?t=259859 |
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#32 |
Senior Member
![]() Join Date: May 2003
Location: Sandown, NH
Posts: 2,820
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Re: Rear End Gear Oil
Hey Shaky !
What part of Maine are you from ? Love Maine, I used to go hunting every yr way up north on the Canadian boarder. Gary
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Gary 72 SWB 4x4 My 72 SWB Build http://67-72chevytrucks.com/vboard/s...d.php?t=259859 |
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#33 |
Six in a row makes it go...
![]() Join Date: Mar 2009
Location: Vacationland: Maine
Posts: 1,346
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Re: Rear End Gear Oil
York County. The rest of Maine calls it "Boston", but I like it. Definitely not as "Bostony" as the southern border of NH!
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67 C20 long step resto: http://67-72chevytrucks.com/vboard/s...d.php?t=342086 66 C10 long step build: http://67-72chevytrucks.com/vboard/s...=1#post3814790 CT to Alaska in a 67 C10: http://67-72chevytrucks.com/vboard/s...d.php?t=399224 “The height of sophistication is simplicity." - Clare Boothe Luce |
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#34 |
Senior Member
![]() Join Date: May 2003
Location: Sandown, NH
Posts: 2,820
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Re: Rear End Gear Oil
Bostony!!! I like the solotude of Northern Maine, but I wouldn't want to live up there, and then I wouldn't want to live in Boston either.... "LOL"
Both are good places to visit though !
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Gary 72 SWB 4x4 My 72 SWB Build http://67-72chevytrucks.com/vboard/s...d.php?t=259859 |
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#35 |
Registered User
![]() Join Date: Jun 2014
Location: Shingle Springs, CA
Posts: 869
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Re: Rear End Gear Oil
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