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04-05 Trans Rebuild & Gearing Option

4K views 6 replies 3 participants last post by  mheyman 
#1 · (Edited)
Early Last summer with 235000 mi on it, my STis trans started, occasionally to make a clanging noise at idle, in neutral, when it was very hot. My clutch literature pretty much tells users to expect trans noises. But this noise was unnerving to me. I didn’t trust a trans making that noise not to grenade at highway speeds. So, I had my transmission rebuilt while I was on vacation. Things I learned:

For anyone who has a high mileage transmission and sees no other reason for the shifter play you have, it’s probably time to have your trans rebuilt. I pulled and replaced mine and let Rallispec rebuild. It shifts like a new car.

https://www.rallispec.com/Transmission Services Price List.pdf

I chose Rallispec because my understanding was/is that they worked with Subaru in early rally days to make the cars trans more reliable, and to keep rally cars supplied. They did a lot of the work on early USDM STI transmissions when there were issues. They are “close” to me as is Subaru US headquarters who they worked with. They seem to have a good reputation in my area for maintenance and builds. They are now the closest place I’d take a modded Subaru to. This makes them one of very few in NJ.

I drove my STI stock, and then suspension replaced (all) and Cobb stage 2 for nearly 100Kmi and always I always found it difficult to shift smoothly. During that time I felt that the 04-05 STIs close 1-4 gearing enabled a perfect ratios in corners.

My STI has been a fully built, moderately powered DD for 4 years. I had become more and more irritated with its' gearing. With far more torque and a wider power band, there was no reason for such close ratios. Also all to often if I wasn’t paying close attention while getting on it in 1-3, I’d hit fuel cut, literally in a fraction of a second. Once this summer off a light I hit it in first, second, and third, right in a row! (story there). Anyway I did minimal questioning and told Dave at Rallispec to I wanted the wider 06+ use the wider gearing. He explained something I didn’t exactly follow, and I didn’t communicate thoroughly. The result was an expensive rebuild that I am now quite happy I did – even if I did not fully plan it. My trans was rebuilt with a Rallispec 2ND-6TH LONG RATIO GEAR SET.

RalliSpec 6MT Long Ratio Kit

• The gearing is user friendly and I can shift smoothly all the time!
• The gears are all useful!
• I shift less from a start and the car is quicker for it!
• I don’t hit fuel cut very often.
• I use 6th only on highways and I cruise at actual highway speeds near 3K. I do shift more between 5th and 6th when there is any traffic.

I am writing this because I now consider that this is a must do for anyone making the most of a truly full moderate build or above GD STI. I am beginning to look for my next car and when I see GDs that I might build, I plan that it will either be with a trans-plant from my current one, or include a trans rebuild as part of the initial build. In other words, I aint goin back to 04 -05 gearing in a built STI.

I am writing this cause no one else is likely to, and it should be known to anyone putting money into a GD. Also note that this is not an advertisement in any way. Rallispec does not know I’ve written this, though I may send a link to Dave. I did want to tell him how happy I was and while I was writing this I realized there was no better way . . .

After 7 years here I think this is the first thread I have started.

Added: 9/13/20 should have been here orrigianlly

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#5 ·
From Dave last night:

"the gearing is the same as the Spec B. The exact part numbers we use are mostly from a JDM Forester STI model (which has the same ratios as the Spec B but seem to have a different heat treatment and we believe may be a little stronger). Some of those part numbers are shared by the USDM 2007 STI as well. We use the uprated carbon synchros for 4th, 5th, and 6th. And all gears are REM superfinished for max reliability and reduced friction."
 
#4 ·
Note that my STI had app 235Kmi on it (now fixed). The post was originally written during a work lunch. I cleaned up a bunch of typos and edited for readability - it needed it.
 
#6 · (Edited)
After a couple of months of driving I am still sold. I will say the 6th is highway cruise only. That means 65+. In my car that's a good thing. Low 60s are a bit high in 5th. But the gearing is so much easier to use and entirely useful.
 
#7 · (Edited)
Been commuting with the new ratios. In terms of performance , I still feel the long ratios are a tremendous step in quickness. They really allow the car to wind out - like other cars!!! That, and its sound is awfully fulfilling.

There is one trade-off though. The gears no longer overlap, and I find myself shifting back and fourth from 5th and 6th a lot because the car is not happy below 65 in 6th. This makes 6th a real highway gear. But, if I run into traffic and things slow down it's back to 5th even if its just for a few moments - because when the moments end, I'll accelerate back to my highway speed.
 
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