Update:

Upon talking to Centaur they use a 80W-90 SAE that they purchase in bulk as Subaru of Canada does not specify any special gear oil for the STi.

So far the semi-synthetic for Crappy Tire is working well, but I'm going to do a full change over this week.

The only fluid at Crappy Tire that meets the 75W-90 SAE and the GL-5 requirements is their semi-syntehtic gear oil. Their regular is 80W-90 SAE.

I'll let ya'll know how it goes.

Hey guys,

I checked my trans. (6spd) fluid level and it is on the "L" of the dipstick. I've got 40,000km on the car so it seems odd that its down so much.

The owners manual says not to mix brands, so does this mean I have to go to Centaur to buy fluid to top up with?

Thanks.

-J

lol i mix royal purple and quakerstate i think it is.

but i wouldn't mix at random

You mix trans fluid or are you talking about motor oil?

-J

trans fluid... motor oil i run penzoil synthetic straight

thanks. Anyone else? Anyone that doesn't have so many "kills" :eek:

lol i haven't killed a tranny since! and mark (wombat north) is the one that picked out the oils for me.. good man that guy :)

oh no! A Northern Albertan and an Aussie :eek: double :eek:

I think I'll pick some fluid up and not worry about it so much.

-J

just to make sure your clear its engine oil that goes into manual tranny's, let me pull out thee old service manual, and I will get back to you on weights

I switched my tranny to 100% synthetic and it shifted poorly. Minor grinds here and there, and first gear sucked. I switched back to conventional oil and it worked much better. If some one can post the "blend", or direct me to where I can find it, much appreciated.

-S.

02. Transmission Gear Oil(1).pdf (http://www3.telus.net/duarpa/02.%20Transmission%20Gear%20Oil(1).pdf)


01. General Description.pdf (http://www3.telus.net/duarpa/01.%20General%20Description(1).pdf)

err i guess i was wrong..

I've tried two different synthetics in the six speed. The sweetest shifts came from plain jane 75-90 dino oil. I'd get it from a Subaru dealer if you can.

The 5 speed responds better to oil "cocktails" and it seems to me that no two like the same exact mix. I tried Wombat's mix in my five speed, and it was a wreck compared to his. The six speed likes the factory stuff. Unless you're looking to reduce parasitic drag for a racing application, I'd stick with it.

02. Transmission Gear Oil(1).pdf (http://www3.telus.net/duarpa/02.%20Transmission%20Gear%20Oil(1).pdf)


01. General Description.pdf (http://www3.telus.net/duarpa/01.%20General%20Description(1).pdf)

err i guess i was wrong..

Gear oil of 75-90 has the same viscosity as 10-30 engine oil. They have different scale numbers for some reason. And of course they have different additives, so they really shouldn't be interchanged without knowing exactly what you're doing.

... good info... good info

Thanks. I'll swing by and pick some up tomorrow.

-J

from what I've read the consensus seems to be that the gear oil from the factory is valvolene 75w90 GL-5 dino oil in the 6 speed. But it sounds like a good time to switch to a syntehtic I'm switching to Motul gear 300, lots of good things have been said about this oil, Rally use it here in Edmonton.

whatever you do... DO NOT use amsoil synthetic. I'm 98% sure that's what killed my last tranny. I went to Jer over @ Rally and got their stuff - much better.... ahhhhh....

hmm yeah i just checked mine out of curiosity, brought upon by this thread and low and behold mine is running super low, below the L mark.. and here I was thinking to myself that i had worn out all three 2nd gear syncross :lol:

wow this car sure loves to gobble up all its fluids

Parts guy at SOC said its just Dextron 3. Not too sure if I spelled that correctly but it should be available at Crappy Tire.

-J

Parts guy at SOC said its just Dextron 3. Not too sure if I spelled that correctly but it should be available at Crappy Tire.

-J
Unless I have missed something here, Dexron III is an automatic transmission fluid.
:confused:
Jer

I figured that out.

Note to all:

Don't get your transmission fluid changed at Subaru of Calgary !!!!!

-J

I figured that out.

Note to all:

Don't get your transmission fluid changed at Subaru of Calgary !!!!!

-J

lol too funny

I figured that out.

Note to all:

Don't get your transmission fluid changed at Subaru of Calgary !!!!!

-J

To be fair, did you specify that you have a manual STi and not the auto STi?

:furious:

Get the lube that the dealer sells. Works the best. It has a propietary additive in it (kinda like LSD addititive but different) & it REALLY works! That's what the WRC team still uses, must be a reason why. BTW, the stuff for the STi 6spd is different from the gear oil for the 5spd MAN. At least according to the STi Japan.

To be fair I was explicit about it being an 6spd in an STi. As well I talked to the parts guy not a service writer.

SOC is also the root of some clutch issues that I'm having so I've become a Centaur person.

-J

bolth subie dealers here in calgary cant be that bad can they?

I think its time i found some investors and opened one up here in Canmore... with performance oriented Staff and tech.. we shall call it "Dirt Subaru" lol or something to do with rally

To be fair, did you specify that you have a manual STi and not the auto STi?

:furious:

lol..... gotta love all those auto sti's running around

I use Castrol Synthetic from Wal-MArt. It shifts alright in my 5spd. I recently bought a couple of bottles of RedLine Superlight Shockproof and I think I will try to make a coctail with that. Is that stuff good for the rear diff as well?

I changed out the tranny fluid to Redline MT-90. Shifts nice to me and no grinding whatsoever. For the rear diff, I used Redline 75-90NS. Got everything at Mopac.

Before I got the Redline stuff, I went to SOC and Centaur and both said that I'd have to buy whatever tranny fluid in HUGE quantities. Bastards were probably trying to get me to bring the car in for them. :(

updated

The WRX STi is filled at the factory with Motul. Perhaps it's only in the engine, I don't know. They have gear oil for every application so I don't know why they wouldn't put in in the transmission and diffs too. I've been using Motul in every high performance vehicle I've owned since I tried it in my supersport race bike back in the early '90's.

Coaster

The WRX STi is filled at the factory with Motul. Perhaps it's only in the engine, I don't know. They have gear oil for every application so I don't know why they wouldn't put in in the transmission and diffs too. I've been using Motul in every high performance vehicle I've owned since I tried it in my supersport race bike back in the early '90's.

Coaster


From the factory the engine is filled with regular conventional oil, I had an analysis done by Blackstone. Only the Moly was high (assembly lube). The rear diff is the only part that comes with a "special" oil. The STi specified part # is K0305Y0900.

I've got Motul Gear 300 going in my 5spd very soon and I have sold the same Motul to a few STi owners who have reported great results. Might be worth trying :cool:

Rob

If anyone local has a six speed with Motul Gear 300 in it, I'd like to beg a ride to see how it is. I've changed fluid so many times its starting to add up. I'd like the next oil to be the "one"

If anyone local has a six speed with Motul Gear 300 in it, I'd like to beg a ride to see how it is. I've changed fluid so many times its starting to add up. I'd like the next oil to be the "one"

If you are comming up for the Rally meet I'll be there and I should have it in there by then.

All the lubricants in my car is Motul and I've been pleased with the results. Haven't looked back and haven't used anything else since.

O.k., I just put in Motomaster semi-synthetic SAE75W-90 gear oil. Now, I'm not too sure if I had factory fluid in there or whatever Centaur buys on bulk but what a difference :eek: !!!

I've only got the morning's commute under my belt but my initial impression is

-smoother going between the gates
-WAY smoother downshifting

I've been starting to question my rev matching abilities of late, but with the new oil things have smoothed right out. I don't know how the Motul feels but unless things go South on me I'm in no rush to try anything else out.

-J

I'm running the same fluid now, after I drained my Redline 75-90NS. Still not as good as the plain jane dino oil. At least for me...