Trany swap/rebuild, help me decide.

well we could just get the welder out and fix that case problem. I would like to see a blown up trans though. and I would have to send out a piece of the case to get the alloy makeup.

i've also heard that the case on the 5spd is the weak link, its prone to flexing under load, which sends the gears into contact at obscure angles and the load is distributed on the gear surface incorrectly. the 6spd apparently has a different case design, and hence is less prone to breaking gears for that reason.

some people say that the RA gears are a bandaid fix for that reason, they just replace the breaking gears with stronger ones, as opposed to fixing the problem at the root.

its like giving someone with childhood issues anti-depressant meds, it doesn't really fix the problem at the source.
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i've also heard that the case on the 5spd is the weak link, its prone to flexing under load, which sends the gears into contact at obscure angles and the load is distributed on the gear surface incorrectly. the 6spd apparently has a different case design, and hence is less prone to breaking gears for that reason.

some people say that the RA gears are a bandaid fix for that reason, they just replace the breaking gears with stronger ones, as opposed to fixing the problem at the root.

its like giving someone with childhood issues anti-depressant meds, it doesn't really fix the problem at the source.
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renowned rally racer Pat Richard is notoriously hard on gearboxes. he's tried everything--RSs, dogboxes, megabucks custom Prodrive units, and box stock STI 6MTs. and the winna -- stock STI 6MT. gears are extra wide, well supported by the case, and hardened. STI 6MT is near bulletproof. however, it's a complex swap due to center diff controller hardware and software being added to a car that originally didn't have it. not that it can't be done, it just complicates things and adds $$$ to the process.

the "well known" weakness of the the std 5MT box is overrated IMHO. it's more of an issue with operator error instead of glaring engineering problems. if you shift mindfully (and run top-grade synthetic lube lke Motul or Red Line), a standard RS or forester box will handle the power output of a EJ20 no problem as long as the clutch is upgraded. ppl tend to hurry the 1-2 and 2-1 shifts and bend selector forks, which leads to Bad Things happening elsewhere in the box.

DG

 
At the previous AutoX in Bath, there was a guy who showed up near the end of it with a Black 03 (i think) WRX. He said that he had RA gears in it. I'm pretty sure his name was Q. I'll have to ask him what mileage he gets in his car on the interstate... That is if I ever see him again. Pedro gave him a STM invite card, but I haven't seen him post on here or anything.

I do understand that I can either have my car raisin-n-git with mondo torque, or get good fuel mileage.

Sometimes people put the regular US-wrx 5th gear in with the RAs for better mpg when cruising.
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So what about that? I know that it would be a taller change from 4'th to 5'th, but I don't use 5'th gear when I'm looking for torque and hp.

How much predicted WHP will you put down?
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My car was previously tuned at XX Tuning in Conn, and put down 230 WHP.

another tack is to change final drive ratio on the car--shorter final drive will pep it up a bunch. your WRX has 3.9 final drive center and R diffs, so one approach is to go with a stock RS or Forester 5MT (nice close ratios, 4.11 final drive) with a 4.11 factory viscous limited slip R diff. you'll have to change clutch bits as well, go with Exedy Stage One clutch disk and used linkage & pedal cluster from the RS or Forester. This option should work out to about the same price-wise as the RA rebuild, esp if you source a used trans and can handle the mech work yourself. Am considering this same swap on my O2 Rex waggie.

Dave G
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I'm also not looking to just make it have shorter gears down low... I'm looking for something a little stronger that would take care of the whole "never go into first until creeping" issue. I don't know how strong Forester or RS trans are and if I was to put a used trans in my car with all that work, it would be a 6mt. I would just wait and save up more before starting the work.

Speaking of not being able to go into first gear well... Does the RA gearset take care of that? That is something that no one has touched upon yet anywhere I have checked out and I have failed to ask this of anyone before now!!

well we could just get the welder out and fix that case problem.
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bingo! WAY cheaper than STI 6MT.

DG

heh, at this rate you could get the whole swap done by somebody else and still have $$ left for some training at Team O'Neil so you can utilize the new-found spunk in your car properly.
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Dave

(full disclosure) I Yam a Team O teacha

 
I can't comment on reliability issues, but as I remember the fellow selling it is in southern NH. I checked his profile once. I would think within a couple hours + - of Portland area.

 
I can't comment on reliability issues, but as I remember the fellow selling it is in southern NH. I checked his profile once. I would think within a couple hours + - of Portland area.
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Yeah I think he is a mod on NASIOC too... could be wrong though.

 
It would be really great if you post here you're final decision and so on so that someone without much knowledge of these things (myself included) could learn your final outcome. And we (I) would have a record of this issue for future reference.

 
yes, you would also need new front halfshafts to finish out the WRX to RS gearbox switch. not sure if you'd need different halfshafts for the 6MT job. (welcome the the wonderful world of swaps!)

no need for a new front diff, it's built into the gearbox. you'd need a 4.11 rear diff to go with the RS trans. if you try to run a gearbox and R diff with different ratios, you toast the center diff. "mmmm, I love the smell of cooked diff in the morning" (it smells just like burnt clutch)

what exactly are your "first gear woes" ?? It's typical of a scooby box to resist the 2-1 downshift for a sec, either learn to double-clutch it or just be a little patient. If it's autoxing you need the quick 2-1 shifts for, then just plan ahead a little! Good high-end synthetic gear lube helps a bunch. Just cramming it into 1st at high revs is a good recipe for a FORCED gearbox swap.
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whatever you decide to do, a swap job means you'd be well advised to leave a little padding in your budget to deal with unexpected bumps in the learning curve.

DG

 
my WRX wagon is a little slow on the 2-1 downshift. I'm getting over it. double-clutch and it's slick as snot. think of it this way....you get paid (or at least don't spend) a couple Gs to learn the double-clutch.

DG

 
what exactly are your "first gear woes" ?? It's typical of a scooby box to resist the 2-1 downshift for a sec, either learn to double-clutch it or just be a little patient. If it's autoxing you need the quick 2-1 shifts for, then just plan ahead a little! Good high-end synthetic gear lube helps a bunch. Just cramming it into 1st at high revs is a good recipe for a FORCED gearbox swap.
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that's sounds like a good decision. Get er dun and forget about it. That 6sp will treat you right.

The delay before kerplunking into 1st is due to stuff spreading out on the gear shaft and slop in the case bearings. Like Dave said that results in bent shift forks, busted gears, and other not-so-good happenings. If funds dont roll in like you planned maybe a used 06 5spd tranny will suit you. The double coned sychro tranny.

What you've described is the exact reason why I got so frustrated with my WRX. The dealer experiences didn't help much at all either. The senior tech at Maine Mall SUbaru told me "you aren't supposed to down shift Subarus." I said "The Hell you aren't!" I told him the rolling to a stop light situation and what if it turned green as I and 10 others behind me arrived at the light. I asked if I was supposed to get run over by the traffic behind me or stop then down shift to 1st then go? He was dumbfounded.

Subarus are very capable, and now the company has improved on a very good thing. I hope your project goes smooth and ends with a smile on your face as you bomb thru the twisties.

 
Heh, I grabbed 1st by mistake at Maine Forest Rally when downshifting from 4th to 3rd...buh-wAAAAAH!!!

fortunatley for me (and for Tulips tranny) it was only momentary brain fade... :
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DG

PS--if 6MT swap doesn't work out like you'd like,, give me the STI box and I'll try to make best of it!

 
yeah That's my deal too. I hate having to roll at a creep into lights that turn green right as I get there, and stuff like that. I also can't just throw an 06 wrx trans in my car because of the speedometer issue. It is run through the ABS and not the trans. I don't know any more about it than that, but believe me, I am VERY interested in it.

And of course you are supposed to downshift, you can't keep going faster and faster while upshifting forever! lol

also, my car has 143K on it, so it's expected that things have worn and will continue to wear. It will last long enough for me to work on the money for it though. It's not going to die, it's more of an annoyance right now. plus I want to run more HP and possibly upgrade to the H-6 turbo swap. That wil be another 5K or so on top of drivetrain swap. And that's if I get lucky and get some good deals.

 
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