Tailhousing compatibility, Phase 1 vs Phase 2?

[skid542]

So I now have the famous Radio Flyer in my possesion. Through it's many ownership iterations it has been converted to RWD. The current tranny is supposedly a 03' WRX 5mt.

The result of that change is that the rear tail housing appears to be shot. I can hear bearings grinding and a very general unhappy sound coming from the rear of the tranny. I am currently assuming that the shot bearings are limited to the final output bearing in the tail housing that controls the shaft going driveshaft.

So, I want to swap out the complete tail housing with another working unit and at the same time restore the AWD system.

I know the center diff's between Phase I and Phase II are different, but if I were to swap out the whole rear tail housing do I resolve the compatibility issues? I.e. can I take the tail housing from my 96' OBW that has shot synchro's and input bearings and use it to replace the tail housing on the 03' WRX tranny? Further, will this affect the final drive ratio going to the rear, i.e. would I need to swap the rear diff to a 3.9 and ditch the 3.54?

Any help here would be appreciated. I won't actually be tearing into things for about a month or so but I wanted to start doing my homework and getting things lined out.

Many thanks in advance.

[skid542]

No takers?

[Matt Monson]

Lee,
You cannot switch over your '96 tailcone because of the 1.1:1 reducer gears used in the WRX gearbox. While you may be able to move them over to the other tailcone based on your description of what's going on there, they may already been fubured.

Let me check. I might still have the parts you need. There was some extra stuff off the '06 core we used in the repair of the WRX gearbox in your other car. I know we used the '06 center diff so I still have an 02-03 one. I may also have the gears you need. I'll sell you this stuff for cheap if I've got it. Call me tomorrow and remind me to look.

[n2x4]

Of course, Matt is correct but I'll add.

Yes, the tailcone/housing will work between phase 1 and phase 2 as long as the corresponding center diff is switched as well.

In your case, the tailshaft from a WRX has the 1.1:1 transfer gears to make the 3.9 front diff work with the 3.54 rear diff.

If you were to swap over the tailshaft from the 96, you would now have 1:1 transfer gears and need a 3.9 rear diff to match the 3.9 front diff.

[skid542]

Thanks for the input guys. The tranny is a system I'm still learning and I appreciate the input. I'll likely be making some more posts with some questions once I have the parts and can start digging into this.

Ideally I would be able to fix the problem with the tranny in the car from underneath but maybe that won't be the case?


Nate, from what you are saying the gears will be compatible within the housing itself and the only change would be the rear diff? That I can handle. This is assuming though the gear coming into the tailcone area isn't fubar'd as Matt eluded to. Hmm... okay.


Matt, I'll give you a call about this today. As always, many thanks. BTW - I finished my last Auto-X of the season last weekend and my tranny is still performing great. I LOVE the controllability of it when it's sliding so many thanks for all the great LSD's .

[n2x4]

Ideally I would be able to fix the problem with the tranny in the car from underneath but maybe that won't be the case?


Nate, from what you are saying the gears will be compatible within the housing itself and the only change would be the rear diff? That I can handle. This is assuming though the gear coming into the tailcone area isn't fubar'd as Matt eluded to. Hmm... okay.

It can be done inside the car - It's really not that bad.

I think you understood what I said, Lee but I'll provide a pic to clarify. To swap between phases, you need everything pictured here (stolen from my center diff how to):


That's the tailhousing, gears, and center diff. You can't mix and match components between phases, you gotta get the whole chunk. Then you can put it in any Subaru 5mt you want.

[skid542]

Nate,

Perfect! That's exactly what I was thinking and all those components are components I'm thinking I need to replace. I've gone over your How-To several times (very well done and it should be added to the Sticky threads).

I figure if the bearings and or gears are gummed up from the RWD conversion the damage should be fairly limited to the tailhousing - or so I'm hoping.

Again, thanks for the help.