Carnage located. Tranny pros please read.

[Kecksauce]

Prior to pulling the tranny from my car, it drove as if the clutch was slipping even though it was fully engaged. If you kept on the gas long enough it would act like it halfway wanted to go, but wouldn't put any power to the ground. Now keep in mind I'm the second owner and rescued the car from the dude who owned it before me, so be nice.


Without further adieu...










Clearly the front diff is tore up from the floor up. My train of thought is that when the front diff took a shit, the viscous coupler in the center diff went soon after. Strangely, the whole rear section of the transmission looks alright, upon a visual inspection anyways.

Considering that this was my first time tearing into a transmission, I'm definitely wondering what you guys think. I have a couple crates full of wrx tranny parts so I just may be able to get this one back on it's feet.

Discuss/debate please

[lucid_door]

OH MY god LOL that's unbelievable! I've never seen a gear so torn up; I wonder why the pinion is all wrecked but the ring gear appears relatively ok?

[Kecksauce]

Your guess is as good as mine man. The ring gear is a little ate up. The teeth are rounded off from the center out a little. If someone can explain the pinion, I'm dying to hear it. I haven't even seen that in grenaded solid axle diffs before.

I'm wondering if ricer dude was donut happy maybe?

[gijonas]

id say one good shock load broke a tooth on the pinion,which allowed the next tooth in line to move into position with even more momentum behind it-so on down the line domino effect.I bet only a few teeth on the ring were involved in the initial incident,however the ring is toast regardless after having that bald pinion ride over it for who knows how many miles.May just have been a bad pinion ,i think these trannys often "noodle" the input before the pinion goes with such load but who knows.Nice carnage BTW.

[evolutionmovement]

Whoa.

[93forestpearl]

OH MY god LOL that's unbelievable! I've never seen a gear so torn up; I wonder why the pinion is all wrecked but the ring gear appears relatively ok?

^ This.


When Derek tore up his front R&P, there were teeth gone from both.



Stranger things have happened though.

[Kecksauce]

Alright, next question. I'm wanting to make the car rwd, is there any way to flat out remove the front diff and call it a day?

[SiCkSTi04]

that is all...

[fishbone79]

Late to chime in... but goddam I'm impressed. He'd have had to seriously womped on that, but I have seen one case where the pinion was "sharpened like a pencil" from grenaded carrier bearings on either side of the housing... Didn't look like that though. In that case, it was still driving the gear, but had about a 1/8" of lash.

There is no elegant RWD solution, but there are ways to do it. Did you pull the viscous coupling on that thing? Was there more purple than the gay pride parade?

[Kecksauce]

Haven't taken the center diff all the way apart yet, but just glancing at it everything looked normal. If I have time this week I'll tear it down and let you know if my transmission came out

[Kecksauce]

And for the record, the rwd conversion needn't be elegant. It's going to be a drift car and I'm well aware of the drivetrain repercussions. Would removing the front diff, capping the holes
from the output shafts and welding the center diff do the job? Or just leave the front together and without axles? I only ask due to the varying opinions on the matter. I have 3 trannys to mod so any help is appreciated!

[skid542]

Wow on the wasted gears :-0.

As far as the RWD conversion goes. Leave the front diff alone. Weld the center diff. Cut your front axles at the CV axle so you end up with stubs. If you don't have an axle in your front hubs they'll blow apart so you have to have something there. This will destroy a transmission though if not done right. I have a tailhousing from a conversion like this where the rear output bearing is completely shot. But if you're aware of it and want to go the route - this is a way to do it. I'm a huge fan of AWD but I'll admit, a RWD Legacy does sound fun .

[Kecksauce]

::UPDATE yO!::

Played around with everything a little today after work and took some snazzy new pictures brought to you by my iPhone haha.

First off, I scraped some of what little is left of that pinion gear off the inside of the case. Yummy.


Then took the center diff apart. The roller bearings (if that's what they're called) are intact and in good shape. The washer/shim looks like it's seen a little heat at one time or another.


Don't quite know what to make of the viscous coupler. A little color on the outside edges, but not more purple than a gay pride parade I don't think.



As far as the welding goes, who wants to do a sweet MS PAINT edit for me and point out what all I need to weld on this guy?



Tailshaft and all it's bearings appear to be good to go!


Lastly, should I be worried about clearance here even if the center diff is welded up and the front axles are left disconnected?


Thanks a bunch for your help. This has definitely been an interesting process!

[skid542]

Looks like you're having fun .

As far as where to weld - when you look into that center diff you see a total of three gears. You have a gear that has a main axis longitudnal and two spider gears that run side to side. Basically what you want to do is weld all three of those gears so they make a single joined piece. How things work is a shaft turns that viscous unit which then turns the spider gears which rotates the gear that has the longitudnal axis which then drives the shaft that goes forward to your center diff. The viscous unit is trying to keep that shaft and the shaft going aft to rear wheels at the same speed. The purpose in welding those spider gears is to force the center diff to turn everything at the same rate removing the need for the viscous unit to try and balance speeds.

Does that make sense? I'm not a tranny expert and there are many more knowledgeable here than me (who I trust to school me on this if I'm wrong) but that is where you'd be welding as I undestand it.


Now with regards to the clearance - make sure you have positive clearance, i.e. nothing can touch. If the gears are that worn then I wouldn't trust them to work together and spin the front stubs like you'd normally have with a RWD conversion. If they're only catching here and there then they're going to be making little metal flakes/chips/debris that's just going to upset the rest of your transmission. That I do know and can say with some certaintity .

[Kecksauce]

Sweet! That's kinda what I had guessed, and I found myself wondering something else: How to weld the gears and keep them from shifting so the viscous unit still lines up with the spider gears. Last thing I need is more jacked up hillbilly teeth in there.

[fishbone79]

Sweet! That's kinda what I had guessed, and I found myself wondering something else: How to weld the gears and keep them from shifting so the viscous unit still lines up with the spider gears. Last thing I need is more jacked up hillbilly teeth in there.

I believe you can tack weld it while assembled (on a phase1) by sticking the tallywhacker of your mig through the holes in side of the center diff housing (turn your gas waaaay up so you swamp the work with low O2 environment). I could be wrong, but I seem to remember this was the way it has been done in the past... You may be able to weld it thoroughly through the side, I'd be wary of things shifting around/expanding and contracting without it being assembled to hold everything aligned in place. There are a couple people on here who have done it, perhaps they'll chime in - I've only read about it and looked at a few that were already welded.