18 STI transmission fluid help

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I have an 18 STI that I bought new in July and I need help with the transmission fluid. From the beginning in the cold or when the car sat for a day or 2 it would be hard to get out of first gear and as the weather started to get colder it got worse. I thought ok maybe ill try the motul gear 300 that everyone raves about. Now its even worse then the factory fill and sometimes I cant get it into gear while driving slowly. I have tried double clutching and rev matching which help some. Thinking about going back to the subaru gear oil or maybe trying something else. It does improve after a mile or 2 but I never had a manual transmission car so stubborn. Even old cars that were beat to death shifted better than this thing.
 
I would definitely take it to the nearest Subaru dealership. That shouldn't be happening.
 
Originally Posted By: wemay
I would definitely take it to the nearest Subaru dealership. That shouldn't be happening.

I rather not take it to the dealer.
 
Originally Posted By: 555
Swepco was recommended to me and it does help. LIC Motorsports can give you the specifics.

Thanks I sent them a message.
 
I have Redline Lightweight Shockproof in my Forester and it is very good, even better in cold weather than the Gear 300 (which I used previously). It's still not what I would consider perfect, but then again my tranny has 220k on it with no rebuilds. Subaru Extra-S and Uncle Scotty's Cocktail did not perform as well as the Gear 300 (in my tranny at least).

See this thread here for more info.
 
What exactly are you trying to do?.. never put it back into first while rolling 2nd is low enough.

Just remember you need a gl-5 gear oil in that transmission.
Its not a honda civic or toyota corolla.

I've had 4 MT equipped subaru they are all like that to a certain extent.

If you never race it or get it very hot you could consider thinning it down with some of the subaru Extra MT 75w80 GL5 they put in the newer forester MTs

sold in 5 gal pails only
https://parts.subaru.com/p/Subaru__/Gear-Oil-Extra-MT-75W80-5-Gallon-Pail/49506107/SOA748V0100.html

But it will never shift like a Civic, or even a focus.
 
I am trying to get it to shift better when cold. I never do try to go into first when rolling. Motul gear 300 is a gl-5. I have owned a LGT as well and put close to 60k miles on that car with 200k total. While the trans was finicky it was nothing like this STI. I have also owned 4 other manual trans cars without issue. T56 in my camaro was the best MT ive owned yet. I also do not think that link you listed is extra-s. Supposedly you can not get extra-s in the US anymore.

Originally Posted By: Rand
What exactly are you trying to do?.. never put it back into first while rolling 2nd is low enough.

Just remember you need a gl-5 gear oil in that transmission.
Its not a honda civic or toyota corolla.

I've had 4 MT equipped subaru they are all like that to a certain extent.

If you never race it or get it very hot you could consider thinning it down with some of the subaru Extra MT 75w80 GL5 they put in the newer forester MTs

sold in 5 gal pails only
https://parts.subaru.com/p/Subaru__/Gear-Oil-Extra-MT-75W80-5-Gallon-Pail/49506107/SOA748V0100.html
 
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Originally Posted By: Spdfrk1990
Originally Posted By: wemay
I would definitely take it to the nearest Subaru dealership. That shouldn't be happening.

I rather not take it to the dealer.



Then you spent a lot of money on a car with a deficient transmission. (previous GR owner)
 
Brand new car, take it to the dealer. Everything should be covered at this point. Could be a bigger problem than the fluid.

I flushed my tranny at 50,000km with motul, never had a problem shifting before or after and Im in Canada where it hits -30c every winter.
 
Originally Posted By: i_hate_autofraud


Watch for binding in the shift linkage it can be cold related too.


I had thought of that as well. I did get the STI sts kit and maybe they got it too tight when it was installed at port. It rows through the gears ok when not moving though.
 
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Remember that the fluid you put in the transmission is shared with the front differential. I'm not sure how different fluids affect the operation of the helical limited slip differential. My 04 has a different type of limited slip front diff and I was warned about what type of fluid is not good for proper operation.
 
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