STi 6mt Swap Question

[keatsdude]

Hello Folks,

I'm in the middle of swapping an 06 STi driveline into my 91 legacy ss. It started as a 5mt, and I picked up a complete STi driveline including tranny, diff, knuckles/hubs, suspension and brembo's. I currently have the 6 mt trans bolted up and the R180 in place, but as I went to connect the STi driveshaft it is about 2 5/8" too short. The legacy driveshaft does not fit on the center bracket holes anymore, it's a little too long. I've seen stuff on the 91 - 94 legacy auto driveshaft, anyone have any lengths or relevant info? Might look into getting my STi driveshaft lengthened, but I'd rather not if I don't have to....thanks!

Keats

[Legacy777]

Check out my 6spd swap details thread towards the bottom of the first page in this forum for lot's of info.

http://bbs.legacycentral.org/viewtopic.php?f=7&t=49917

[keatsdude]

Josh,

Thanks for the reply. That thread looks to be very helpful, that would have been nice to see before I dove into this project! I already tapped/drilled for the starter to bolt up, and my connectors seem to be fine using the old 5mt harness. I'll look at my driveshafts tonight and try to compare. From what I recall, the STi front section fits, but the rear is to short. The Legacy front section is to long, and is to long overall. But I need the STi flange for bolting up to the R180. Also, looking at the legacy driveshaft I didn't think I could seperate it and use another section (up front). Initially I was thinking I could use the STi front section, with the legacy rear. But the R180 flange would need to be put on the legacy rear section...

Hmm...this is all speculation sitting at work. I'll take a look when I get home tonight and try to make sense of this all. Did you swap front control arms as well? Looks like I have to shave the front mounts a little to make them fit, but it should work.

[Legacy777]

No, I just put in the axle stubs and used my legacy axles. I did not upgrade to the R180 rear end or STi front hubs for the very reasons you are finding out.....there's much more work that has to be done......and the benefits/improvements IMO aren't that great unless you're going for BIG power.

[keatsdude]

Yes, it's definitely a bit more work. But Brembo's and aluminum control arms are gonna be pretty neat. Not big power in my near future, more about reliability and strength.

Back to the driveshaft issue, it looks like the lengths in your thread are correct in my situation as well. My 5mt legacy driveshaft is about 1.5" too long, and the STi 6mt is about 2.5" too short. If I switch to the "newer" auto legacy, can I use the front section of my STi driveshaft? The legacy 5mt does not connect in the center the same way. Is the newer legacy similar to the legacy 5mt design? Looks like the STi utilizes a u-joint, where the legacy is a cylinder type slip joint.

If this is to confusing to read, do you happen to have a picture of the whole "newer" auto legacy d/s? I've got a picture of my STi d/s I can post if it would help...

I'm about ready to just cut my STi d/s and weld it! haha, that should work just fine.

[Legacy777]

I'm not sure I completely follow you.

Does the rear section of the 6spd driveline match up to where it should be to properly mate with the front section? Since the pinion flange is different, that seems to be more the driver there. The 6spd or front section of the auto trans driveline should work just fine up front. You'd just need to see how they fit together.

If you could take some pictures, that may help me understand things.

Here are all the pics from my 6spd swap and the ones specific to the driveline measurements.
http://www.main.experiencetherave.com/s ... spdswap/09

[keatsdude]

Josh,

Thanks for your help. I finished up the driveshaft issue late August, just wanted to update this post quick in case somebody runs into this in the future.

I ended up using the front section from the STi d/s, the rear section from an auto legacy wagon ('98 I believe), and took the flange off the old r160 and put it on the r180 so the d/s mated correctly. I had to enlarge the holes on the 98 rear d/s section to mate to the flange to the STi d/s front section. It worked will since both d/s were concentric (the circle in the middle matched). It doesn't seem to vibrate at any speed.

[Legacy777]

Thanks for following up and letting us know how it turned out.