Transmission and rear diff fluid

sebast120 · 11-19-2008, 04:13 PM

Anyone knows if I really need to use that LSD oil from japan that subaru says I should use on my 2004 STi??? Or can I just use royal purple synth.

And for the transmission, Subaru says I should by their GL-5 synthetic 75W90 at 40$/1L, they sell 4L for that price anywhere else.

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Engmus · 11-19-2008, 05:36 PM

Rear diff fluid should be a STRAIGHT 90W. I recommend Motul 90PA or the Subaru 90 weight fluid.

Frontdiff\Transmission any GL-5 75w90 works for the 6mt, its not very picky. I recommend Motul gear 300 75w90

kidwitdawrx · 11-19-2008, 05:42 PM

im dont know much but im learning a lot now cause i blew my stock wrx up and am putter he back together as we speak. I have spoken to many subie specialists and they all told me the same for all my questions on what fluids to use. The motul is the most recomended and they told me to stay away from royal purple. DS1 motorsports dylan and jeff sell it for $60 for 4 liters. I just bought some trying to get as much life as I can out of my tranny.

mikeythejew · 11-19-2008, 05:48 PM

BTW, if RP is sooo good, why do they list what tranny fluid to use in what vehicle but not subaru?

http://www.royalpurple.com/transmission-chart.html

Engmus · 11-19-2008, 05:58 PM

Meh, I know alot of people who swear by Royal Purple. I have more faith in Redline oils and Motul oils for botique, or specialty oils.

satan's sled · 11-19-2008, 06:29 PM

is there a magic number when the fluids should be replaced? i have hearded 30k....is that for the normal DD? what about when tracking the car...or is that one of the first things you should do along with oil and brake fluid as well?

sebast120 · 11-19-2008, 06:54 PM

thks for the replys guys, Engmus, wath do you mean by straight 90 for the rear diff???

bulwnkl · 11-19-2008, 10:02 PM

He meant to say that the bottle should say SAE90 (rather than 75W90 or 80W90).

OTOH, if an SAE90 meets your needs, Schaeffer's #267 is flatly superior to anything that's been mentioned in this thread for outright strength and durability of the differential. Only question is: Does your STi use a clutch-type LSD, or is it viscous like every other Subaru? If clutch-type, then the 267 may not be suitable; you'd have to ask Schaeffer.

Engmus · 11-20-2008, 12:51 PM

I like Schaeffers fluid, but I wouldn't say they are clearly superior without evidence to back something like that up. Especially when competing with Motul.

Seeing how he has a 2004 Subaru according to his profile its more then likely a clutch-type LSD.

Satans Sled, I do my trans and diff every 10-15k. Its easy, not very expensive and good preventative maintenance.

bulwnkl · 11-20-2008, 02:27 PM

I don't say Schaeffer is superior in a blanket way. The #267 specifically is absolutely unbelievably tough in terms of film strength and wear control. However, it's only available as an 80W90 or various ISO grades, so there are many reasons why it may not be suitable for a given application. Do NOT use it in the transmission. Also, the moly di-sulfide in it may or may not be a good idea in a clutch-type LSD. That's a question for Schaeffer.

Motul makes some very fine products, but I've never seen anything that shows me something extra-special about their performance compared to other very-high-quality fluids available in the USA. Mostly, what I've seen is that Motul is selling the perception of technical superiority and eurpoean mystique (that tends to try to imply technical superiority). 'Technical superiority' is what got the French overrun on the Maginot line during World War II (and other times & places) by a vastly 'inferior' German army. So, I'll counter by asking to see something about Motul that shows they're any better in real service than a variety of other things I've used or seen in analysis?

sebast120 · 11-20-2008, 02:59 PM

Sooooo, I think I'll just go with the freackin oil from Japan that Subaru says I should use

sebast120 · 11-20-2008, 03:04 PM

Hoo, and I do have the LSD rear differential.

Engmus · 11-20-2008, 06:31 PM

Quote:

Originally Posted by sebast120

Hoo, and I do have the LSD rear differential.

All STi's have LSD rear ends, its just two different types. The 2004 is equipped with the Suretrac diffs.

bulwnkl; im at work so i cant dig right now, but i'll do what I can when I get home.

savsuby300 · 11-21-2008, 12:16 PM

Hey hold up, what's wrong with the Royal Purple? Is there something I need to know?

Engmus · 11-21-2008, 01:05 PM

^Nothing is "wrong" with Royal Purple, its a sound, solid lubricant.

Just in the term of good, better, best.

It would be between good and better.

Its perfectly suitable for DD and light track usage.

I wouldn't however run it in something I abused daily.

11-19-2008, 04:13 PM	#1
sebast120 Scooby Newbie Member#: 194765 Join Date: Nov 2008 Vehicle: 2004 WRX STi silver	Transmission and rear diff fluid Anyone knows if I really need to use that LSD oil from japan that subaru says I should use on my 2004 STi??? Or can I just use royal purple synth. And for the transmission, Subaru says I should by their GL-5 synthetic 75W90 at 40$/1L, they sell 4L for that price anywhere else. * Registered users of the site do not see these ads.

11-19-2008, 05:42 PM	#3
kidwitdawrx Scooby Newbie Member#: 190156 Join Date: Sep 2008 Chapter/Region: Tri-State Location: Westchester, NY Vehicle: 2004 Impreza WRX Java Black Pearl	ditto im dont know much but im learning a lot now cause i blew my stock wrx up and am putter he back together as we speak. I have spoken to many subie specialists and they all told me the same for all my questions on what fluids to use. The motul is the most recomended and they told me to stay away from royal purple. DS1 motorsports dylan and jeff sell it for $60 for 4 liters. I just bought some trying to get as much life as I can out of my tranny.

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11-19-2008, 05:36 PM	#2
Engmus Scooby Specialist Member#: 115645 Join Date: May 2006 Chapter/Region: MAIC Location: South-East PA	Rear diff fluid should be a STRAIGHT 90W. I recommend Motul 90PA or the Subaru 90 weight fluid. Frontdiff\Transmission any GL-5 75w90 works for the 6mt, its not very picky. I recommend Motul gear 300 75w90

11-19-2008, 05:48 PM	#4
mikeythejew Scooby Specialist Member#: 141672 Join Date: Feb 2007 Vehicle: 07' wrx Uncle Scotty 5W30	BTW, if RP is sooo good, why do they list what tranny fluid to use in what vehicle but not subaru? http://www.royalpurple.com/transmission-chart.html

11-19-2008, 05:58 PM	#5
Engmus Scooby Specialist Member#: 115645 Join Date: May 2006 Chapter/Region: MAIC Location: South-East PA	Meh, I know alot of people who swear by Royal Purple. I have more faith in Redline oils and Motul oils for botique, or specialty oils.

11-19-2008, 06:29 PM	#6
satan's sled Scooby Newbie Member#: 166281 Join Date: Dec 2007 Chapter/Region: SWIC Location: land of tires, az Vehicle: 2006 STI CGM	is there a magic number when the fluids should be replaced? i have hearded 30k....is that for the normal DD? what about when tracking the car...or is that one of the first things you should do along with oil and brake fluid as well?

11-19-2008, 06:54 PM	#7
sebast120 Scooby Newbie Member#: 194765 Join Date: Nov 2008 Vehicle: 2004 WRX STi silver	thks for the replys guys, Engmus, wath do you mean by straight 90 for the rear diff???

11-19-2008, 10:02 PM	#8
bulwnkl Scooby Specialist Member#: 41070 Join Date: Aug 2003 Location: Arizona Vehicle: 2005 Black Tiger (Black Turbo Baja)	He meant to say that the bottle should say SAE90 (rather than 75W90 or 80W90). OTOH, if an SAE90 meets your needs, Schaeffer's #267 is flatly superior to anything that's been mentioned in this thread for outright strength and durability of the differential. Only question is: Does your STi use a clutch-type LSD, or is it viscous like every other Subaru? If clutch-type, then the 267 may not be suitable; you'd have to ask Schaeffer.

11-20-2008, 12:51 PM	#9
Engmus Scooby Specialist Member#: 115645 Join Date: May 2006 Chapter/Region: MAIC Location: South-East PA	I like Schaeffers fluid, but I wouldn't say they are clearly superior without evidence to back something like that up. Especially when competing with Motul. Seeing how he has a 2004 Subaru according to his profile its more then likely a clutch-type LSD. Satans Sled, I do my trans and diff every 10-15k. Its easy, not very expensive and good preventative maintenance.

11-20-2008, 02:27 PM	#10
bulwnkl Scooby Specialist Member#: 41070 Join Date: Aug 2003 Location: Arizona Vehicle: 2005 Black Tiger (Black Turbo Baja)	I don't say Schaeffer is superior in a blanket way. The #267 specifically is absolutely unbelievably tough in terms of film strength and wear control. However, it's only available as an 80W90 or various ISO grades, so there are many reasons why it may not be suitable for a given application. Do NOT use it in the transmission. Also, the moly di-sulfide in it may or may not be a good idea in a clutch-type LSD. That's a question for Schaeffer. Motul makes some very fine products, but I've never seen anything that shows me something extra-special about their performance compared to other very-high-quality fluids available in the USA. Mostly, what I've seen is that Motul is selling the perception of technical superiority and eurpoean mystique (that tends to try to imply technical superiority). 'Technical superiority' is what got the French overrun on the Maginot line during World War II (and other times & places) by a vastly 'inferior' German army. So, I'll counter by asking to see something about Motul that shows they're any better in real service than a variety of other things I've used or seen in analysis?

11-20-2008, 02:59 PM	#11
sebast120 Scooby Newbie Member#: 194765 Join Date: Nov 2008 Vehicle: 2004 WRX STi silver	Sooooo, I think I'll just go with the freackin oil from Japan that Subaru says I should use

11-20-2008, 03:04 PM	#12
sebast120 Scooby Newbie Member#: 194765 Join Date: Nov 2008 Vehicle: 2004 WRX STi silver	Hoo, and I do have the LSD rear differential.

11-21-2008, 12:16 PM	#14
savsuby300 Scooby Newbie Member#: 189232 Join Date: Sep 2008 Chapter/Region: South East Location: Savannah, Ga Vehicle: 1995 Nissan 240SX Dead in the shed.	Hey hold up, what's wrong with the Royal Purple? Is there something I need to know?

11-21-2008, 01:05 PM	#15
Engmus Scooby Specialist Member#: 115645 Join Date: May 2006 Chapter/Region: MAIC Location: South-East PA	^Nothing is "wrong" with Royal Purple, its a sound, solid lubricant. Just in the term of good, better, best. It would be between good and better. Its perfectly suitable for DD and light track usage. I wouldn't however run it in something I abused daily.