DCCD transfer section on spec.B 6MT

Has anyone swapped the transfer section of the spec.B 6MT for a DCCD unit? I know several have swapped the whole trans to STI with DCCD.

Will this work, is there any reason it wouldn't? Seems like you should be able to just swap the whole tail section out and add a DCCD controller.

Any strange gotchas with things like VDC? Driveshaft compatibility, anything?

You could. The output splines on the input shaft is the same IIRC, so the diff itself should work, and using the transfer gears from the STi would probably work as well.

It'd be expensive, though. The diff alone is $2k from the dealer, and finding used ones that aren't broken is time consuming. And you'd need a DCCDPro controller, of course.

VDC wouldn't care at all.

Driveshaft should be the same as the stock 6MT Spec-B unit.

Seems like it'd be cheaper than swapping the entire trans though.

There's a lot of DCCD center diffs for sale over in NASIOC land for reasonable prices. However I've never seen anyone selling the actual transfer housing or transfer gears, and whatever else may be inside.

Just something I was thinking about, I'm in no hurry, but I could certainly go fishing for a while for someone who trashed their gears in a 6MT and doesn't plan to rebuild.

In looking through forums for sale, including history, I think finding an entire transfer section+gears/etc is about impossible.

What isn't impossible though is buying a full 6MT, swapping the transfer section, and re-selling it as a non-DCCD 6MT. An awful lot of people don't bother even hooking up a DCCD controller after they do the swap. Finding one of those people and doing a trade seems plausible.

Might be a long term project for me. I'm also looking for a full DCCD transmission for my RS, so maybe I'll poke at the plausibility more once I get into that.

http://downloads.bustedfingermotorsports.com/08WRX/STI%20Transmission/6MT%20Manual%20Trans%20&%20Diff.pdf

Here its saying that the front diff is a 3.9 final drive and the rear is a 3.545 final drive so the center diff has to do some kind of manipulation. It doesnt go into detail on the year but i thought that some years of STis had a 3.9 rear as well.

I thought the spec.b was a 3.9 rear.

http://downloads.bustedfingermotorsports.com/08WRX/STI%20Transmission/6MT%20Manual%20Trans%20&%20Diff.pdf

 

Here its saying that the front diff is a 3.9 final drive and the rear is a 3.545 final drive so the center diff has to do some kind of manipulation. It doesnt go into detail on the year but i thought that some years of STis had a 3.9 rear as well.

 

I thought the spec.b was a 3.9 rear.

That was one of the main reasons I was curious. I wasn't sure if you'd be able to simply swap the transfer gears from the spec.B center to the DCCD center to maintain the 1:1. 2004-2005 STI 6MTs are 1:1 anyhow, but if you get a 2006+ (which I would prefer for the mechanical center when open) you need to do something about the1.1:1.

Of course, you could alternately replace the R&P on the rear diff and use 3.54 I guess.

I dont know on the gears. I do know that I had read that the tail sections were nearly the same, the diff being that the STI variant has the hole drilled out for the DCCD control wiring. It would be great if you could just use the Spec.b gears. Tehre is A DCCD up for sale on nasoic right now for 645 shipped.

http://forums.nasioc.com/forums/showthread.php?t=2213237

Yeah, the centers are easy to find, finding the transfer case itself is not. I've never had one apart, so hopefully someone who has can chime in on how feasible it is.

From everything I've read, it should work.

BTW, is the link the actually diff with gears, or is that just the unit that controls the torque transfer?

That's just the diff itself, nothing else.

I emailed the guy in the link from the previous email and this is what he said.

Yeah the output shaft from my 06sti transmission does not fit the legacy spec b viscouss center diff that I have. Now I just have the viscouss center sitting on a shelf . I did this all on my 07 wrx, its a swap of course. I didn't even hook up the dccd because if you change it to 80/20 on the street you will just end up destroying your center diff. The dccd is for the tarmac only. I was told this by several subaru techs who had replaced customers dccds because they messed with it on ca's messed up roads. Hope this helps.

-Chris

Looks like we wouldnt be able to do it even with a tail housing?