when manual transmissions break...

redlinedeath · #1 11-13-2007, 09:51 PM

alright, so i was wondering, i know a wrx 5sp can handle the svx better then a legacy 5sp. my question is, what part or parts break exactly? does anyone know exactly what it is that goes wrong on these transmissions under hard driving?

jeffast · #2 11-13-2007, 09:53 PM

no idea i have a legacy 5spd in mine and i have had no trouble whats so ever. I also have an ACT light weight flywheel and an Excedy stage one racing clutch. young tom would be the person to ask he has broken evreything once.

redlinedeath · #3 11-13-2007, 10:17 PM

haha, i already bombarded him with tons of questions about 5spds yesterday, hopefully he wont get to annoyed with me

reason i ask is i was thinking of getting a legacy trans and sending the gears and all the internals to get cryo-treated. itd be alot cheaper then a wrx trans, and maybe stronger?

jeffast · #4 11-13-2007, 10:28 PM

honestly i am no expert. i would like to know if the wrx internals are the same as a standard 5spd i have theorised, that they are the same, but i don't have the budget to buy and tear down trannies for a stupid reason like that

redlinedeath · #5 11-13-2007, 10:31 PM

ha, i wish i had the money to do something like that. i know the gearing is different, but i dont know what it is that makes the wrx trans stronger. to be honest, i just started studying up on how manual transmissions work yesterday night, so im getting a basic understanding of it (thanks to how stuff works) but need more insight. till the last day, transmissions were always a complete mystery to me. thank god for being bored, and getting me on this weird kick to figure it out!

NiftySVX · #6 11-13-2007, 11:41 PM

Usually, Higher strength manual transmissions are just simply bigger than the others. Synchronizers are bigger and there are more of them, etc. A major difference in a weak transmission and a stronger one is in how the gears are made and what the exact metallurgy of them is and how they are made. Most manual transmissions don't fail because the gears fail (Like the engine had so much power that it stripped the teeth off the gear) but because they can't handle the surges in the torque and because the shifting isn't smooth, because of driver error or because something is worn out of spec.

redlinedeath · #7 11-13-2007, 11:52 PM

that being said, ive been trying to research synchros, as to my understanding each manufacturers approach is slightly different regarding their synchros. i understand what they do, matching speeds and all, but what exactly are they? subarus synchros i mean? i coudnt find a diagram of them online or anything, so ive no clue how they look, is it just a friction material like a clutch, or what?

Hondasucks · #8 11-13-2007, 11:54 PM

I know that the Legacy Turbo 5 speeds have the internals shot peened, but I don't know if that's it or not...

AFBeefcake · #9 11-14-2007, 08:42 AM

I got two busted wrx tranys. One had a bustes 2nd gear and the other has a busted 3rd. Both were 2002 tranys and broke when in wrx's. 2003 or 2004 have wider gears and should be stornger, but abuse will brake them like anything.

redlinedeath · #10 11-14-2007, 05:51 PM

a guy i know got his synchros carbon treated, as he should be hitting 500-ish hp in his civic, and doesnt want to chance that. what the hell is carbon treating? anyone know?

Wikedjuggalo · #11 11-14-2007, 07:42 PM

Quote:

Originally Posted by redlinedeath

a guy i know got his synchros carbon treated, as he should be hitting 500-ish hp in his civic, and doesnt want to chance that. what the hell is carbon treating? anyone know?

I assume they meant something like this ?
Carburizing: A process used to case harden steel with a carbon content between 0.1 and 0.3 wt% C. In this process steel is introduced to a carbon rich environment and elevated temperatures for a certain amount of time. Because this is a diffusion controlled process, the longer the steel is held in this environment greater the carbon penetration will be and the higher the carbon content in these areas. The part is then quenched so that the carbon is locked in the structure. The hardness is moderately increased, but it can be hardened again through flame or induction hardening. It's possible to carburize only a portion of the part by covering it in copper plating or coating it with a commercial paste
from wikipedia. Basically adding carbon to parts to make it stronger, I assume it is probably expensive.

redlinedeath · #12 11-14-2007, 07:51 PM

that actually sounds kind of interesting. worth more research. im pretty sure it is pricey. he sent just his synchros it, it was 300 not including shipping.