Diff Oil? - Page 2 - Alfa Romeo Bulletin Board & Forums
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post #16 of 18 (permalink) Old 11-04-2018, 10:04 AM
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Originally Posted by Gubi View Post
The 75W90 has the LSD additives for clutch-type LSDs and the 75W90NS does not. This is all on the Redline pages and tech articles, yet folks seem to keep getting it wrong.


"Contains additional friction modifiers for suitability with clutch-type limited slip differentials - for most LSDs, no additional friction modifiers are required"
Ok thanks thatís what I thought, hence me questioning.
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post #17 of 18 (permalink) Old 11-04-2018, 10:06 AM
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FROM EXPERIENCE 75W90NS works well with LSD diffs and you can use the same oil in your gearbox - no need to keep two different oils. I read the stuff online as well and I bought a bottle of Redline friction modifier that makes 75W90NS progressively more like 75W90 and I was going to add some if I had any clutch chatter in the LSD. I have never needed to add any to any of my LSD axles or transaxles and I have had a few of them. But as we all know reading stuff on the internet beats years of practical experience.
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post #18 of 18 (permalink) Old 11-04-2018, 10:54 AM
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You can use what you want, but the statement "the NS is for clutch type LSDs" is incorrect and further confuses folks about the difference in formulation. People should read the Redline tech bulletin as it clearly explains the differences and tradeoffs between the two fluids.

I've tried a lot of gear oils over the years, myself. My experience is that the Spider diff is pretty indifferent, just use a GL5. I use Swepco 201 GL5 in the Spider gearbox and diff (and the transaxle in my former Milano) and like it better than the Redline 75W90NS, but that's just my take.


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