Quick question-LOST in Specs! GL5

Plus 2 Discussions
1

I am a bit lost in differential fluid land. I’ve read numerous posts and ready to plunge forward with Redline GL5 for my '71 Lotus Elan Plus 2 Diff. However I’ve an obvious question but don’t want to screw this up.

Should I get the Red Line 57904 (75W90) Synthetic OR

(58304 75W90 Non-Limited Slip Synthetic Gear Oil

Of course, the Elan is Non-limited slip. But the previous threads don’t seem to mention this as an alternative.Thank you!!
Mike

HERE’s the write up on the NS OIL for non-limited slip diffs:

Designed for transmissions and transaxles - helps to slow synchros for easier shifting across a broad temperature range
Popular in Ferrari, Porsche and Subaru transaxles
Muscle Car applications like Ford Top Loader, Muncie transmissions, Borg-Warner T-10 and Super T-10
Contains extreme pressure additives like our 75W90 GL-5 oil, [b]but lacks friction modifiers to balance slipperiness[/b]
Improved copper corrosion protection to prolong synchro life
Helps with lock-up on weak limited-slip differentials-compatible with Red Line Limited Slip Friction Modifier for tuning slippage
Also used with clutch-type LSDs in racing for maximum lock up
Recommended for API GL-5, GL-6, MT-1, MIL-L-2105E and SAE J2360
Non corrosive formula, safe for use with all synchro materials

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2

The 75W-90 NS is “Non slip” not “non limited slip”… it is intended for limited slip clutch type diffs that a normal road Elan does not have. Also for transaxles that need a GL5 oil but also have syncros that need a less slippery oil to work properly.

The 75W-90 is what you want for your Elan diff.

cheers
Rohan

3

Thank you Rohan!
I am personally very appreciative of your insight and guidance. Cheers!
Mike