Thread: B15 Tranny Carnage

how did they break gears?
I think they are feeding you some, because the gear stacks are very well supported. Likely they just broke the case to pieces, but who knows when you drop 40ft lol. Tell them you'll take it for scrap heh heh. Make sure to post pics of "what happens when a transmission drops 40 ft"

These tranny's aren't that heavy compared to some, but that is alot of weight falling that far. I didn't get to see it but I'll ask tomorrow when I go get the other one. Maybe they will just give me the parts.

Got the B15 tranny pulled all the way apart and mostly cleaned up and removed the ring gear from the different. Also got my old old B14 tranny pulled apart and the ring gear off of it. Gonna take the new tranny apart when I get it tomorrow then take the stacks to a transmission shop to have them swap the 5th gears. I have pics I will put up later.

Gear stacks out of the B15 trans:


Almost all the way apart (ring gear is separated now as well):


I know it wasn't necessary to take the shift linkage part out, but there was a bunch of teeth around there that I wanted to clean out.

I would like to know how to get the roll pin out of the shift linkage rod inside the transmission, there looks to be a hole in the case for this purpose but I don't know how to remove whatever is in there to get this roll pin to have enough room to come out.

you've gotta use heavy shockproof in your tranny. Seriously it will last 5x longer.

approximately how much power are you making?

I do plan on it this time.



I have no idea. I will get it dyno'd, maybe. My fastest trap speed was with a GTi-R T28 @ 23-25psi and it was 120mph. My car doesn't have interior or audio equipment. I figured it was around 350whp then, but now I have a tad larger turbo (GT2860RS disco potato ) and it pulls a hell of a lot harder.

New donor tranny (sorry for dark pic):



I will tear into it this weekend. I am scared about pulling the fifth gears off as I don't know what to expect with these synchros, but I really want the looong 5th gear.

Hmm I wonder why some guys never break b13/b14 transmissions. I think its gotta be driving style.

Better luck to you with the new gears.

why not mix? the popular fluid to run in a subaru is 3qt light weight shock proof, 1 qt motul gear300.

mix some motul 300 in with the heavy weight and that will keep it lubed when cold.

I have a b15 sr20 trans how does the shockproof compared to the mt-90 shift between the two? I might take out my mt-90 and upgrade to the shockproof

Having had one of these apart, it is my opinion that the heavy shockproof would be lubricating enough. I assumed the passages were small, but they are plenty big enough for the thick fluid to pass through. I may throw some MTL in there though, haven't decided yet.

400lb ft of torque breaks things. I think weight is a big issue. Im running a 4dr SEL at 2680lbs.

Could be sprung clutch too, but I've broken transmissions on sprung as well. Rolling on throttle. No clutch dumps.

I think some people just make more power than other's "claims"

Or perhaps the dyno's up here read much lower than others.