which tranny fluid?
09-28-2003, 07:26 PM
#1
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which tranny fluid?
i have a stock 2003 wrx, closing in on 9000 miles
for the past 2000 miles or so first gear has been grinding when i try to engage it. at first it wasnt that often, but now its almost everytime, im not driving the car hard at all. in fact its boring me how much im babying the car now (i only shift into first from a dead stand still). ive taken the car to subaru twice and the've checked out the tranny and found nothing wrong. they want me to sit on it until it becomes a bigger problem, which just pisses me off, cause i know that later on there will be chipped tooths (caused by wateva is wrong) and they wont cover it under warranty. bastards. anyway, ive read in some threads that changing the tranny fluid might solve my grinding problem.
-so which fluid should i choose?
everytime i try to research fluids i get my mind blown with differentials and 75W and stuff soooo if you guys could help me out i would appreciate it.
-again i have a 2003 manual WRX completely stock.... (for now)
thanks
-having to use 2nd instead of first from a roll makes me wanna kill someone
for the past 2000 miles or so first gear has been grinding when i try to engage it. at first it wasnt that often, but now its almost everytime, im not driving the car hard at all. in fact its boring me how much im babying the car now (i only shift into first from a dead stand still). ive taken the car to subaru twice and the've checked out the tranny and found nothing wrong. they want me to sit on it until it becomes a bigger problem, which just pisses me off, cause i know that later on there will be chipped tooths (caused by wateva is wrong) and they wont cover it under warranty. bastards. anyway, ive read in some threads that changing the tranny fluid might solve my grinding problem.
-so which fluid should i choose?
everytime i try to research fluids i get my mind blown with differentials and 75W and stuff soooo if you guys could help me out i would appreciate it.
-again i have a 2003 manual WRX completely stock.... (for now)
thanks
-having to use 2nd instead of first from a roll makes me wanna kill someone
09-29-2003, 01:29 PM
#2
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I think www.cobbtuning.com had a descent writeup on how different synthetic oils preform in the 5MT.
There are also a couple of other live threads now talking about it.
I've also found that double clutching first gear seems to help if you want to get into it while rolling.
Jason
There are also a couple of other live threads now talking about it.
I've also found that double clutching first gear seems to help if you want to get into it while rolling.
Jason
09-30-2003, 11:41 PM
#3
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There have been many threads regarding this very topic lately... and no conclusive...conclusions. You'll have to read up and decide for yourself. Of course, doing any "research" and reporting on it is always appreciate 
jason
jason
10-01-2003, 08:37 PM
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Last edited by ImprezaVA; 10-01-2003 at 08:45 PM.
10-03-2003, 11:34 PM
#6
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Im running a 50/50 mixture of redline MT-90 and 75W90NS in the gearbox. I switched to the redline at 12k miles. I didn't have any grinding or shifting issues but I did notice a signifigant difference. The shifting was much smoother as was engagement of first and reverse. Even my wife could tell the difference. I'm at 21K miles now and can still feel the difference. I love to downshift just to feel how smooth it is.
10-04-2003, 12:23 AM
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Redline MT90 is not proper for Subaru gearboxes. It is a GL4 fluid, and Subaru recommends GL5. If you want to run redline, stick to plain 75w90 (which is actually a little TOO slick, hard on the synchros) or Lightweight Shockproof. Be forewarned, once you add Shockproof, you never really get it out. The other option is to continue using the OE fluid- it works just fine when it's clean and fresh.
10-04-2003, 01:50 AM
#8
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I realize that the MT-90 is a GL-4 fluid and therefore not recommended for the wrx. But I wrote redline and asked if their gear oils were compatable, to which he answered yes. I had read that the 75W90NS was a little to slick for the synchros and some people were having grinding issues. I also heard that people were having excellent results with the MT-90. I wasn't comfortable going with a 100% GL-4 fluid so I decided to try a blend. I figured if I mixed them I could get the protection of the 75W90NS with the frictional characteristics of the MT90. It worked perfectly. I actually used 2 quarts of 75W90NS and 1.7 quarts of MT90, but I probably could have gotten similar results with only one quart of MT90. Anyway, I couldn't be happier with the results and I'll do it agian next time I change the gear oil.
10-04-2003, 06:46 PM
#9
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The more I read these threads about the trans oil, the more I believe that a blend would be preferable. The reason for the GL-5 requirement is due to the fact the oil must lubricate the front differential. Ring and pinion gears require slicker oil. If we just had to worry about transmision syncros/gears then GL-4 rated oil would be just fine. I guess Subaru opted for GL-5 to maintain protection with some sacrifice to shifting smoothness. Maybe by blending we come to a acceptable medium between GL-4 and 5.
10-05-2003, 12:42 AM
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Originally posted by Portland Dave
I guess Subaru opted for GL-5 to maintain protection with some sacrifice to shifting smoothness. Maybe by blending we come to a acceptable medium between GL-4 and 5.
I guess Subaru opted for GL-5 to maintain protection with some sacrifice to shifting smoothness. Maybe by blending we come to a acceptable medium between GL-4 and 5.
BINGO. Any, and I mean any, gear oil you choose is a compromise between bearing protection and synchro operation. They have directly opposing needs- gears/bearings need slick, synchros need sticky. Helping one hinders the other. Personally, I would rather protect my gearset from shock loads by smoothing out the shifts (better synchro operation) than by trying to lube the gears and bearings the best at the expense of shift feel and smoothness. That is just my opinion though.
Last edited by Kevin M; 10-05-2003 at 12:45 AM.
10-06-2003, 01:07 PM
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Originally posted by BAN SUVS
BINGO. Any, and I mean any, gear oil you choose is a compromise between bearing protection and synchro operation. They have directly opposing needs- gears/bearings need slick, synchros need sticky. Helping one hinders the other. Personally, I would rather protect my gearset from shock loads by smoothing out the shifts (better synchro operation) than by trying to lube the gears and bearings the best at the expense of shift feel and smoothness. That is just my opinion though.
BINGO. Any, and I mean any, gear oil you choose is a compromise between bearing protection and synchro operation. They have directly opposing needs- gears/bearings need slick, synchros need sticky. Helping one hinders the other. Personally, I would rather protect my gearset from shock loads by smoothing out the shifts (better synchro operation) than by trying to lube the gears and bearings the best at the expense of shift feel and smoothness. That is just my opinion though.
jason
10-06-2003, 01:24 PM
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No. I'm going to go eith GL5 Lightweight Shockproof. Not the absolute best for wear protection, but it helps the synchros, which means less shockloads on the gearteeth which means less likelyhood of breakage. I can handle wearing out my bearings after 100k instead of 150k for that, especially since I know for a fact I'm going to break it before then. 
10-06-2003, 04:34 PM
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I was under the impression that redline shockproof was not a GL-5 fluid. Does anybody know if that is the case? I just checked out the redline website and it did not specify. They did mention all the gear oils that were GL-5 rated (75W90NS etc...) and also which ones were GL-4 approved. But I couldn't find anything on the shockproof.
10-26-2003, 02:17 PM
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Just switched from Redline 75w90ns to Motul Gear 300. I cannot recommend the Motul enough. I was a Redline fan for 10+ years, thier MT90 and MTL are great, but they just don't have a product correct for our trans. Switch to the Motul, you won't regret it