Differential and Transmission Fluid Change

[Plasma]

Hi everyone,

I have looked through this forum and others and some of the most useful info came from here.

Just looking for a final confirmation before I purchase this oil - I think I have it correct.

I have a 2006 Outback XT 5-Speed with about 117k miles.

This is what I plan on using:

5 Speed Transmission Fluid 3.7 QT GL-5 Redline 75W90NS - GL-5 no friction modifiers, 1 Gallon

Rear Differential 0.8 QT GL-5 Redline 75W90 - GL-5, 1 Quart

Are these two oils the proper ones for the transmission and rear differential?

Also, for the front differential, I believe it is tied in with the transmission so changing the transmission fluid does the front diff at the same time. Is that correct?

If so, is the rear diff different from the back? The back seems to need fluid WITH friction modifiers. The transmission does not, which means the front diff will also not have friction modifiers in the fluid. Is that how it is supposed to be?

Any help would be greatly appreciated!

Thanks...

 

[2000Trooper]

For the transmission you'll need the MT90 which is 75w90 gear oil however it's API GL-4 which is universally what almost all manual transmissions take. GL5 will make your transmission not shift because its additives make it too slippery for the synchros to work. Not to mention the possibility of the LSD additives eating up the brass synchros.

The GL5 fluid will have the friction modifiers for your rear end so you shouldn't have to add any modifiers.

In short GL4 for manual trans, GL5 for differentials.

 

[2000Trooper]

Correction, I looked it up and it does take a GL5 fluid, so your choice is correct. Should have looked it up before hand.

 

[benjy]

you can get Redline recommendations on their web or call + talk to a REAL PERSON, good stuff for sure!!

 

[SubieRubyRoo]

I've tried many fluids including the Redline across my 4 (now 5 as of last night!

) Subarus. In the manual trans the best I've had was Motul Gear 300, followed by the Redline 75W90NS. The rear differentials have always gotten Gear 300. Really, either fluid you will not likely be disappointed.

 

[Plasma]

Originally Posted by SubieRubyRoo
I've tried many fluids including the Redline across my 4 (now 5 as of last night!

) Subarus. In the manual trans the best I've had was Motul Gear 300, followed by the Redline 75W90NS. The rear differentials have always gotten Gear 300. Really, either fluid you will not likely be disappointed.


Ok, so 75W90NS is definitely the right one for the 5-speed.

And is this correct for the rear diff? Rear Differential 0.8 QT GL-5 Redline 75W90 - GL-5, 1 Quart - this one has friction modifiers.