Which trans oil are people using around here in 5MT?

[20psiMR]

Thats the plan. The shop that did the tranny would have had to pull the axles (at least you do in the evo, ive done 10 of those or so) so they should warranty it. Im not too worried about it, just dont want her to run low while driving around. I plan on changing it as soon as I get home from Oklahoma and we get the seal fixed.

I use german castrol syntorq LT, its 75w85 GL5 and serious butter. The stock fluid in the 6 speed evo is 75w85, and this is the only one I have found that matches it completely and performs way better. You can get it at quad4x4.com but its expensive, 35 bucks for 2 quarts. This is the same stuff used in the nv4500 trannys that had overheating issues before they switched to the syntorq. GM syncromesh is the same stuff actually, but its cheaper and this is the german variant from quad4x4, who knows what GM might add to their jugs. Dodge also started putting this in the Viper tranny so you can get the mopar stuff too, and a guy on the evo forum has been sending his in to blackstone every 10k and they have written great stuff about it back to him. Thats whats going in the subie too =P

For the transfer case and rear diff, I change that every 10k and use stock mitsu diaqueen LSD which is a GL4 75w90. I might check out the motul 300v though, its good stuff just expensive. But the diaqueen does rock, and I get it for 35 bucks a gallon at Allison. He wanted 50 but I talked him down hehe. I'll probably just use that in the subie too, it would probably work really well. Too many people have "deathwhined" and summarily grenaded their tcase and diff by using anything other then stock. Tranny you can improve with non-stock fluids, but its a costly mistake if you go cheap on the tcase/diff.

[sperry]

What's a transfer case?

...Point being, I'm hesitant to take a gear oil recommendation for a Subaru gearbox based on EVO gearbox performance. They're of quite different designs.

[20psiMR]

Subaru is also using junk penzoil/valvoline too so take that with a grain of salt. Poing being is its a GL4 75w90 with an LSD additive for hypoid gears. I could talk all day about fluids, Ive done my homework. Different design I would argue, they both run hypoid gears with Limited slip differentials. Just for further knowledge, a transfer case is the same as a center differential. Different terminology, same part. Any other questions you need answered while were going to school?

[Dean]

Not trying to start a battle or nit pick, but while they may sit in the same location in a drive train, a transfer case is significantly different than a center Diff. A TC splits power front and rear evenly at one or more gear ratios. A center diff is just that a differential of some form with fixed or variable torque split usually at a single gear ratio.

I do not claim to know anything about Evo transmissions, but it is unlikely that the gearset and synchros are the same on the two gearboxes.

Those are the weak point of the Subaru trannys and many of us make a conscious choice to use the LW shockproof even though it is a GL-4 fluid to protect the transmission and make shifting significantly smoother, especially 1st gear downshifts. This may cause additional wear on the diff, but to the best of my knowledge, I have never seen even anecdotal evidence of that wear or failure prior to tranny failure.

Shared fluid forces compromises, and especially on the 5MT, I would use whatever will protect the transmission at all costs.

[sperry]

Originally Posted by 20psiMR

Subaru is also using junk penzoil/valvoline too so take that with a grain of salt. Poing being is its a GL4 75w90 with an LSD additive for hypoid gears. I could talk all day about fluids, Ive done my homework. Different design I would argue, they both run hypoid gears with Limited slip differentials. Just for further knowledge, a transfer case is the same as a center differential. Different terminology, same part. Any other questions you need answered while were going to school?

While we're in school, what would you recommend for the 5MT's front LSD? water chummed

[20psiMR]

Loaded question, the tranny on a subaru shares fluid with the front diff.

[Kevin M]

Originally Posted by 20psiMR

Loaded question, the tranny on a subaru shares fluid with the front diff.

Which is why (with the exception of Lightweight Shockproof) you should not recommend a GL4 gear oil for it.

Chris, having looked over your Evo briefly at Stead and heard a bit, you seem pretty knowledgeable about them. But please consider that we're right when we say that what you know about Evos doesn't really apply to Subarus. If you go farther than ""turbo 4 cylinder AWD sedan" when describing either one, you have nothing but differences. They really couldn't be more different from a mechanical standpoint, though they arrive at a very similar point in terms of performance. Most of us who chime in on threads like this have passing knowledge of Evos, and what we know tells us that we need to know a lot more to give advice the way we do with the Impreza. Now, I don't want to say that you know nothing about Subarus and should keep your mouth shut- just that if you have such knowledge, it doesn't come from experience with the Evo.

Hopefully, you'll stick around and be one of the limited number of people here who really can dish out the right answers when Evo questions come up.

[20psiMR]

Also, just to clarify....I never recommended anything to be honest. I gave out what Im using in the evo and why. The MR 6 speed has a weak point of failure on track and thats the 4th gear tooth. It will shear and let go once it overheats on track conditions. The syntorq is the only one Ive found that doesnt turn to crap after a track day. I stated thats whats going in my girls subie, but I never said you should put it in yours. Like dean said, and I totally agree, they are different beasts. The syntorq might be more in line to the 6 speed oil used in the STI. Honestly I dont know, which is why I am on these forums, to learn. Girlfriend bought a subie so I need to pick up what I can to help her since Im an evo tech sponge. I know the diaqueen will work well because its specifically designed for hypoid gears and LSD's and meets the weight and GL specifications in the owners manual of her car as well. Also, thats the same oil used in the evo 5mt, so I wouldnt doubt it would work well in her trans as well. The 6 speed evo is the only one that calls for "Mitsubishi Super Diaqueen 75w85" so I like my pick with the syntorq as it matches the weight and GL spec for that as well. Thats all, not really trying to start a war but honestly theres some of you that come off quite smug, and Mary has already told me she is about done posting over here because she feels unwelcome.

[20psiMR]

Originally Posted by Kevin M

Which is why (with the exception of Lightweight Shockproof) you should not recommend a GL4 gear oil for it.

Chris, having looked over your Evo briefly at Stead and heard a bit, you seem pretty knowledgeable about them. But please consider that we're right when we say that what you know about Evos doesn't really apply to Subarus. If you go farther than ""turbo 4 cylinder AWD sedan" when describing either one, you have nothing but differences. They really couldn't be more different from a mechanical standpoint, though they arrive at a very similar point in terms of performance. Most of us who chime in on threads like this have passing knowledge of Evos, and what we know tells us that we need to know a lot more to give advice the way we do with the Impreza. Now, I don't want to say that you know nothing about Subarus and should keep your mouth shut- just that if you have such knowledge, it doesn't come from experience with the Evo.

Hopefully, you'll stick around and be one of the limited number of people here who really can dish out the right answers when Evo questions come up.

You must have misread, because I specifically stated that Castrol Syntorq is GL5. Also, I just looked it up and the regular 75w90 diaqueen is also a GL5, for some reason I was thinking it was GL4. Im in oklahoma so I dont have the jug in front of me. Like I said, an exact match for what SUBARU calls for in the service manual. So I agree I may not know as much about subies as you guys being an evo lover, but I figure subaru knows enough about their own cars to print it in the service manual, but call me crazy.

In evos we use the cocktail of 1 quart heavyweight shockproof and 2 quarts MT90. Im not a big fan to be honest, and that is ONLY for the 5 speed. 6 speed is toast if you throw that in.

[Kevin M]

Originally Posted by 20psiMR

You must have misread, because I specifically stated that Castrol Syntorq is GL5. Also, I just looked it up and the regular 75w90 diaqueen is also a GL5, for some reason I was thinking it was GL4. Im in oklahoma so I dont have the jug in front of me. Like I said, an exact match for what SUBARU calls for in the service manual. So I agree I may not know as much about subies as you guys being an evo lover, but I figure subaru knows enough about their own cars to print it in the service manual, but call me crazy.

In evos we use the cocktail of 1 quart heavyweight shockproof and 2 quarts MT90. Im not a big fan to be honest, and that is ONLY for the 5 speed. 6 speed is toast if you throw that in.

Yep, I misread. I blended two posts together and decided you said she should use a GL4. My bad.

And you're right about MT90. I would only use it in low torque 2WDs. Anyway, forgive us for getting on guard. We've seen too many guys who know a lot about Evos, or think they do, come in and start spouting off about how to tune Subarus. Great tuning on a street Evo is pretty much exactly the opposite of what Subys need, especially if one's Evo knowledge comes from old school DSM tuning. So, please forgive us (or at least me!) for jumping to conclusions a bit. We aren't a tech mecca here, so we try extra hard to refute poor advice when it shows up, and sometimes before it actually has.

[Dean]

Chris, I hope you and Mary (Or is it Mare?) stick around. We really are mostly harmless. Many of us are here because we can't stand the noise level on Nasioc, I-Club, etc. That is why we pick on Cody, Juice and others when they get too random or homophobic. So, if she could dial down the chaos a bit, it would go a long way to keep Austin from locking her threads.

The WRX MT5 is a fragile beast if remotely abused. I put 30K of probably 25-30% track and autocross miles with no problems, but I know how to shift and only used the factory fluid and LW shockproof.

The factory fluid is some magically stuff that I believe is only available in 50 gallon drums and even most dealers don't use or carry it. Since Subaru would have to give away their fluid if they specified it, they specify generic GL-5 gear oil instead because of the diff.

The diff is not the weak point, so the search was on for something that would save the trans from braking and smooth out shifts while not sacrificing the diff. You can go read the countless threads on Nasioc on it, but the choices come down to some cocktail, LW shockproof or maybe the Motul, all with basically zero science and lots of anecdotal evidence averaging out to a crap shoot.

Try downshifting the 5MT to 1st at more than 5-10MPH or getting it in gear in the cold. If you like it, leave it. If you have to add or replace fluid, do the research and make a choice.

Personally I think the cocktails are silly as they have no science at all behind them and god knows what the additives and bases in each actually do chemically when combined. The LW shockproof or GL-5 Redline products would be my first choice because I have had great success with their products over 12,000 track miles in 4 cars and they have a very low BS/snake oil quotient in their sales and tech info.

I like Motul fluids for brakes, but have no personal experience with their oils, but would be willing to try if I didn't like a RL product.

My last choice would be anything off the shelf at Kragen or easily obtained from a mass retailer locally except Summit which carries much of the good stuff. They are one of the few bright spots you will find about Reno from a performance parts perspective vs. LV. 9:00-9:00 7 days a week, you can get a lot of good stuff.

Let us know what you end up with and how it works.

[20psiMR]

Dean, I agree 100%. Im not a big fan of the cocktails myself. I know the shockproof mt90 deal works well in evo 5 speeds, but I just dont like how sticky it is in the cold. Works well in Vegas because we never see sub 40 temps lol. Im with you on the motul too, I use RB600 for brakes, but never used anything else. Ive heard nothing but good though, but those frenchys charge a buttload for their fluids lol. (Im french I can get away with that hehe). As far as off the shelf penzoil/valvoline, I used to work at henderson chevy way back in the day and have seen what penzoil does to a motor after 50k miles. Its wax based (the motor oil) rather then petroleum, and leaves alot of gummy residue (or at least it used to, when I was wrenching 10 years ago for a living).

We have done the exact same thing on the MR 6 speed, theres a thread on evom that is 60 pages long and the title is "Trackwhores with MR 6 speed" which is devoted solely for us track guys that abuse our trannys. Im with you dean, I track but Im good on my car, I still have 36k on my stock clutch where normally guys are blowing them at 10. But when guys like Razorlab (brain at GST, im sure you guys know him) grenade 4th gear on the straight at Thill after 4 laps, you know it has to be mechanical. Temp sensors have been added by guys and the consensus is that certain fluids overheat more then others. He was running BG syncroshift, and I would stay far away from that because another guys 4th gear did the same on BG. Someone elses grenaded running the redline cocktail, so I shy away from that as well although I think its more to do with the size of the tooth rather then fluid. Like you said though, protect the trans at all costs. A bunch of trials have been ran on that syntorq, and it has gone through the ringer quite well. After two trackdays it was sent to blackstone and was still strong according to them, so thats what I stick with. Some guys are trying out the amsoil, but honestly Im not fond of being a guinea pig on a $6000 mistake. On that note, if you guys say the lightweight shockproof works well in the wrx Im all ears hehe. She will be doing some light autocross as well, and she is still getting used to driving stick again.

[A1337STI]

Subaru actually makes a Subaru -S gear oil my friend switched over to that in his 07 WRX TR and loves it. i drove his car around and agreed it's good. I think he bought a gallon or two of the stuff. he had some metal bits come out of his transmission the first time he changed his fluid (org fluid at like 10k miles) so he wanted to flush out his tranny a few times. (hence buying a few gallons) Anywho the stuff works great (and it's even from Subaru) its their S gear oil or super S ... it has S in it. probably the suff they use in the STI. I've also used red line in my rally car.. works good too.

[van]

How much gear oil do I need, How many qts ?

[cody]

Click

[van]

clickthanks

[cody]

Well you get the idea anyway.

Also, mysubaru.com might have your owner's manual in PDF if you don't have one.

[SteveM]

Well, all this gear oil talk got me thinking about changing mine. If I ordered the 20 liter barrel of the Subaru Extra-S from genuinesubaruparts.com, would anyone want to buy some from me? I mean I can spot the $150 for it, but it would be nice to use it all up and not have to store the container until I change my gear oil again in 100,000 mi.

[cody]

I'd like to try it. I'll have to check but I think I'll probably be due for a change by the end of the Summer.

[20psiMR]

Originally Posted by SteveM

Well, all this gear oil talk got me thinking about changing mine. If I ordered the 20 liter barrel of the Subaru Extra-S from genuinesubaruparts.com, would anyone want to buy some from me? I mean I can spot the $150 for it, but it would be nice to use it all up and not have to store the container until I change my gear oil again in 100,000 mi.

I do it after a hard track day, so if you do any of those you would probably go through more then that hehe. At least every 10k for me, even if not tracking.

[Kevin M]

Originally Posted by van

How much gear oil do I need, How many qts ?

You have the OG AWD Impreza case, so I would think that the WRX amount is pretty close. Add 3 then add the 4th slowly and keep checking the dipstick. IIRC older Imprezas used not quite 4 quarts.

[bigrobwoot]

Unfortunately I found this thread the day after I changed my tranny fluid. Somehow I got what should go in the tranny mixed up with what should go in the diff, and I put the redline 75-90 in my tranny instead of the lw shockproof. Is this bad, or just less than ideal?

[cody]

75-90ns or 75-90? Supposedly you can put anything in the rear diff and it should be fine. I'd change them out though if I were you.

[bigrobwoot]

I used 75-90. I didn't put anything in the rear diff cuz I though I had the wrong stuff. But I thought sperry said that 75-90 was what belonged in the rear diff on the first page? I'm confused...

[cody]

Redline 75-90 does belong in the rear diff. Redline 75-90NS is probably fine too though. As I said, our rear diff is not picky as per what I've read on the internet. I have Mobil-1 synthetic 75-90 in my rear diff (which is probably comparable to Redline 75-90).

I'd say you're okay with the Redline 75-90 in the gear box as long as you can shift without grinding. The thought is that the 75-90 is just too slick for the synchros but if you can shift without grinding, you're fine.