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YOUR RESEARCHRedline oil and Limited slip diffs???
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Suggestion
Changing the fluid from stock to Redline didn't make any difference in that regard (or any other percievable way).
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Suggestion
per Redline's recommendation I've been running 75-140 in the dif and 75-140NS in the tranny.
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Suggestion · Original poster
This thread makes it sounds like C4s do NOT have LSDs, relying on the PSM instead, and so the NS-type oils are fine, but you need to run friction modifiers in LSDs.
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Suggestion
You could conservatively run OEM fluid which I believe would solve the issue, and fine for street use.
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Suggestion · Original poster
This thread makes it sounds like C4s do NOT have LSDs, relying on the PSM instead, and so the NS-type oils are fine, but you need to run friction modifiers in LSDs.
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I just want to know if I should use 75W-90NS in my trans. It has a slight grind from 3rd to 2nd when the trans is cold, and it's downshifted aggressively. Upshifting at any time/aggression, or downshifting at any time/agression when hot is just fine.
Any suggestions?
I searched many of the threads on pros/cons of redline 75W-90NS trans (gear) oil.
This thread makes it sounds like C4s do NOT have LSDs, relying on the PSM instead, and so the NS-type oils are fine, but you need to run friction modifiers in LSDs.
https://rennlist.com/forums/996-foru...t-the-lsd.html
But then a dude who runs a cup car with an LSD runs the NS oil without issue.
https://rennlist.com/forums/996-gt2-...nsmission.html
Is it a safe bet my car (I just purchased an '01 C4) doesn't have an LSD? (I build 60's and 70s cars, and on a straight axle it's easy to find out, just jack up the rear, trans in neutral, and spin a wheel by hand and see what the other does. But on a transaxle???)
Then there was a link about the redline NS oils (non-slip), being TOO sticky for syncros (link below). Others say it helps them out much better than those oils that have friction modifiers in them. (1%-3% being best).
https://rennlist.com/forums/996-gt2-...dline-oil.html
(third post down)
TIA for helping the newbie!!
Don't all C4s have LSD? This is the purpose of AWD, a viscus center diff coupling front and rear axles with an open differential would not be very functional.
You could conservatively run OEM fluid which I believe would solve the issue, and fine for street use.
per Redline's recommendation I've been running 75-140 in the dif and 75-140NS in the tranny. You can e-mail them youself and ask.
My tranny doesn't like to be shifted fast into 1st and second when cold, but I found that if I let the car warm up a bit longer before taking off on a cold morning it's fine. Changing the fluid from stock to Redline didn't make any difference in that regard (or any other percievable way).
