WRX gearbox questions

[Soobidoo]

hey guys, only new to this site, my mate got me onto it, suparoo i think his name is. anyway.

Ive got the 1998 WRX, and as most people tell me, the gearboxes are made of glass... HAHA. was just wondering if it ever does come to the bad outcome that the gearbox does happen to die on me, what would be my best replacement for it, it feels pretty good at the moment but im fairly easy on it, unlike most WRX owners. mainly coz i dont wanna do the cost of buying a new one, ive been told that my best bet is a new STI 6 speed... for about 6 grand... but ive seen other people put "dog boxes" and such in and was just wondering, although i also have seen a guy put a $11,500 rally box in, but yea, not going to that, thanks for any feedback...

Tobez'

[seagull]

You gear box would be a 3.9 ratio ( aussie ) 3.9 front 3.54 rear > yes mate they are crap .

your gear box would be worth $800.00 > $1100.00 c/w diff

You can get RA sti 6 speeds for $4000.00 non DCCD , you can use the x member from your box & fly wheel & clutch .You will need a 6 speed tail shaft ( I have one ) & your starter motor will need some small mods to make it fit


better on the pocket is a V3 4.444 gear box , there strong

I hope this helps

[tex]

I don't mean to be rude but if it sounds like everyone else is getting rid of them then thats your cheapest option get a spare then you can give the old one as much s**t as you want I used to hava commodore with a hot 6 and 4 banger running gear (yes they do exist) went through too many uni joints But my point being is if you drive it like a human it'll last longer than you have the car!

[Cam]

wait a minute, 3.9 front 3.54 rear? How does that work? Reducer in box?

[Soobidoo]

ok, well yea, so there are a few mods to makin a 6 speed fittin then, ive just been told they are pretty much indestructable but yea, so the V3 is off what model? and thats still a 5 speed i gather? ive seen one wrx in a mag lay claim to 4 gearboxes in 10 months so i dont really want to be spending that much money so frequently. if it does happen to die on me i just wanna do it once and proper. its feeling pretty good still, like its alot better than most other wrx's i think, but yea

[seagull]

Tex , changing subaru boxes is not like a holden + its not a 4 x 4 drive line under load

yes cam the rear out put has a drop gear

Yes the V3 is an STI box & it is a 5MT , get hold of 02 STI 6MT it has a surtrack VLSD in the front these are 3.9 ratio front & rear

[Gannon]

Hey Tobey, glad you could join us..

We'll have a 3" lift and mud tyres on ya ride in no time

[discopotato03]

Yes the REX and the heart of glass .

The progression from L to Liberty to Impreza gearbox wise didn't include major stregthening because there are limits to what can be achieved with a production box .
Like many AWD boxes the subaru one started out as a front wheel drive one to which they added transfer gears and the output shaft to drive the rear differential . Because the torque outputs of the early engines was low and the cars fairly light they got a reasonably compact lightweight gearbox .
So from front wheel drive it became 4WD and some have the extra reduction on the front of the mainshaft to give dual ranges . Aside from a few minor internals it basically got a bit longer and the centre differential (+ visacous drag) was placed in front of the transfer gears instead of behind like the AWD L gearbox .
In time Subaru developed the RS Liberty and Impreza WRX with the same basic gearbox meaning more torque from EJ turbo engines and substantially heavier cars than say an L series . From memory the early Lib RS is something like 1340 Kg and the Later WRX's heavier again .
The boxes don't seem to have problems with standard power outputs so long as the clutch is to factory spec and the car not abused . The std clutch is safety valve so to speak and it generally gives up before the transmission does . Subaru obviously knew that the system is fine in std form (they put a warranty on it) but once you start down the higher performance road and with heavier duty clutches as far as they're concered your on your own .
Most manufacturers at this stage try a few things like wider gears and higher durability steels but there comes a time when they run out of space in the std case and there's no where left to go . In competition gearboxes the dog engagement coupling sleeves are much narrower than a syncro hub so that frees up as much space as possible , but most people would never put up with
the backlash on the street even if they could time all the gearchanges right . Even this method doesn't make a Rex box indestructable simply because the cases cant take large enough diametre gears and shafts . The real answer is to move the shaft centres further apart and use larger diametre gears .
This aside the Subaru AWD is an indirect three shaft box and it doesn't have the shaft or case rigidity of more serious efforts (gearbox wise) like an Evolution Lancer or a Pulsar GTiR . Also because the Subaru box is long and sort of skinny it tends to twist under high torque or shock loads which allows to shafts and gears to move out of alignment and they damage bearings and break gear teeth .
In serious factory works type form they don't do this but then again they don't use a production transmission either .
If you do a bit of searching at places like NASOIC Rexnet etc you could most likely find out whats involved in the later 6 spd box conversion but for the little I've read its pretty expensive .
The few I know of who want to drag race and win toss the manual for some kind of auto/semi auto gearbox and then they live longer (gearbox) .

Other than that for a road car it's probably a lot cheaper and easier to live with mild power outputs and drive the thing sensibly .
If you require a car that's going to be driven hard always then the same era Evo is I think a better basis in fairly std form . In the long run developing a Rex to be as durable won't cost any less its just that you spend more time in the car rather than under it .

Cheers A .

[Gannon]

There is actually little difference between the l series manual box and the liberty/impreza gearbox. The gearsets are actually interchangable. The only real difference is the rear output section and the viscous centre diff like dp03 said.

Actually, there isnt much difference between the 4EAT auto of the l series and the early Lib auto as well

[Soobidoo]

wow, thanks guys for the input, gannon, 3 inch lift kit and it might be back to stock height ey? hehehe.... bloody low cars....

[Captain Obvious]

be nice to that box and it should last ages, as in no rev limiter lauches and 4 wheel burnouts!!!! smooth gear changes it should be good, yes they are called glass gear boxes, but most of the guys that break then are running stupid amounts of HP and are track racing the cars!!

bryan

[Gannon]

You cant really compare an AWD gearbox to a 2WD one.

In a 2WD vehicle, the tyres are usually the weak point and usually results in a burnout, but in an AWD it takes almost twice the power to break traction and thus the tyres are no longer the weakest link.

The clutch is usually next but if its non factory, the gearbox takes the full brunt of the engines torque and breaks

[Soobidoo]

no silly launches... awwwww. hehehehe, nah, only hit rev limit a few times, and that was coz first gear lasts all of about 2 seconds, stupid bloody thing.... hahaha.. oh and revvin out 2nd gear to 120km. just too much fun not to do silly things, HAHAHAH... no its ok, i love her and ill cherish her and i shall call her wendy..... hahahahhaha... shes my baby