Redline Oil Gurus: Subaru gear oil question

dezlpwr

dezlpwr

Joined
Feb 22, 2009
Messages
280
Location
Gig Harbor, WA
Is there any harm in putting a gear oil designed for limited slip differentials in a non limited slip differential? My Subaru Crosstrek manual calls for a 75W-90 GL-5 oil to be used in the rear diff. It is not LSD. I was planning on using Redline 75W-90NS in the front diff/transmission. It is a 6 spd manual and they share a common sump. Would there be any harm if I use the Redline 75W-90NS in the rear diff also or would I have better protection using the regular Redline 75W-90 gear oil in the rear diff?
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dezlpwr said:
After doing more research, I think I'll go with the Motul Gear 300 75W-90. Seems like it does well in the Subaru manual transmissions and rear diffs.👍
Click to expand...
Cant seem to get multiquote to work

Motul is a good choice I ran it in 3 subarus. The redline is ok too.

Stay away from forum based blends and mixes.. I know for awhile they were mixing the shockproof with whatever and calling it some kind of blend.

IIRC extra MT is a thinner gl-5 gear oil. So it may shift different when its extra cold out..
I had no issues except the skyrocketing price with motul gear 300.
2011 Forester, 2015 forester, 2013 outback (all MT)
 
Why dont just follow redline recommendation ? MTL for manual trans and standard 75W-90 at rear differential ? Are we more knowledgeable than the oil producer ?
 
kr_bitog said:
Why dont just follow redline recommendation ? MTL for manual trans and standard 75W-90 at rear differential ? Are we more knowledgeable than the oil producer ?
Click to expand...
Redline MTL is not compatible with subaru MT.
you need 75w90NS for a redline product.
Subaru has combined sump design that shares front diff with MT.. This requires GL-5 for the hypoid gears.

I have emailed redline to see if their product recommender is wrong.
 
Last edited:
kr_bitog said:
Why dont just follow redline recommendation ? MTL for manual trans and standard 75W-90 at rear differential ? Are we more knowledgeable than the oil producer ?
Click to expand...
Subaru changed their oil recommendation to 75W-50 GL-5 in both the manual transmission/front diff and rear diff. It appears as though Redline has not updated this change in their application recommendations on their website. That's why I was asking my question about what to use now.
 
Rand said:
Redline MTL is not compatible with subaru MT.
you need 75w90NS for a redline product.
Subaru has combined sump design that shares front diff with MT.. This requires GL-5 for the hypoid gears.

I have emailed redline to see if their product recommender is wrong.
Click to expand...
I emailed them also. No reply. I do believe the recommendation is outdated since Subaru changed to a 75W-90 GL-5 recommendation in everything. I was going to use Motul 300 75w-90 but I can't find it anywhere. I agree with you, the Redline 75w-90NS will work in everything.👍
 
dezlpwr said:
I emailed them also. No reply. I do believe the recommendation is outdated since Subaru changed to a 75W-90 GL-5 recommendation in everything. I was going to use Motul 300 75w-90 but I can't find it anywhere. I agree with you, the Redline 75w-90NS will work in everything.👍
Click to expand...

Outdated might be the wrong word. Subaru has speced only gl-5 for as long as I can remember in any of their shared MT+Diff applications.
 
dezlpwr said:
I emailed them also. No reply. I do believe the recommendation is outdated since Subaru changed to a 75W-90 GL-5 recommendation in everything. I was going to use Motul 300 75w-90 but I can't find it anywhere. I agree with you, the Redline 75w-90NS will work in everything.👍
Click to expand...
They don’t respond on weekends, I’m sure
 
Rand said:
Outdated might be the wrong word. Subaru has speced only gl-5 for as long as I can remember in any of their shared MT+Diff applications.
Click to expand...
On this part, I dont really trust Subaru recommendation, they backtrack the spec going back to 75w-90 after their Extra MT cause excessive wear and noise for the rear differential.
 
kr_bitog said:
On this part, I dont really trust Subaru recommendation, they backtrack the spec going back to 75w-90 after their Extra MT cause excessive wear and noise for the rear differential.
Click to expand...
What years did they recommend extra MT for the rear diff.
I was more into it in the 2005-2017 subaru era.
back then the fanciest thing was subaru Extra-S.

I got some from dealer and it shifted like crap.. went back to redline. then motul.
 
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