6spd Swap Details Thread

[Legacy777]

Updated the first post with install information regarding the DCCD Pro controller.

[Dominator]

Josh, this thread is great. I'm planning on swapping a 6-speed into my SS soon. I'm bookmarking this page for sure. I love how meticulous you are with your photos and write-ups.

[Legacy777]

You're welcome

[chochocho]

What front axles would fit after the swap?

Looks like both my front drive axles are leaking/ripped

[Legacy777]

If you put in the axle stubs, the stock Legacy axles work fine.

[chochocho]

If you put in the axle stubs, the stock Legacy axles work fine.

so these items plus the driver and passenger side front axles for a 91 legacy?

6spd axle stubs - Qty. (2) - 38415AA110
Axle stub circlips - Qty. (2) - 805329010
LH axle seal - Qty. (1) - 806730042
RH axle seal - Qty. (1) - 806730041
LH axle
RH axle

[Legacy777]

You don't necessarily need to replace the axle seals, but it's probably not a bad idea. The down side is that you have to unscrew the bearing caps to replace the seals. So it's kind of your call. If you're going through the hassle, I'd also suggest replacing the outer o-ring on the bearing caps.

As for the bare minimum, you need the stubs & circlips.

[czei]

Thanks for documenting this! How can you use the stock legacy rear diff when the stock is 4.11 final drive ratio and the 6MT is 4.44?

Anyway, I'm to decide between installing an LSD and stronger center diff into a 5MT or just buying a 6MT. The target application is rallyx and maybe stage rally in the future.

5MT:

* Can control front LSD pre-load and setup just for dirt.
* No car mods needed to make it fit.
* The extra strong center diff should be fine for dirt only.
* Not as strong or durable as the 6MT
* Not sure on price of having qualified transmission guy do the install.

6MT:

* Requires some car mods to get it to work.
* Maybe not as aggressive for dirt?
* DCCD would be more flexible for combined street/dirt
* Seen some used versions between $2,500 and $4,500.

[Legacy777]

The stock turbo legacy rear diff is 3.9 and so is the 6MT.

[lor]

Hello guys!

Have somebody info what is the wire size at the dccd?
I would buy connector to my dccd but i dont know witch size i need.
https://www.corsa-technic.com/item.php? ... ory_id=105
Yeh bigger is better i know.

Thanks and regards

[Legacy777]

Hi Lor,

The current going throught he DCCD controller isn't very much. I would suspect the stock wiring is around 20 gauge. I think the smallest I have and typically use for applications like this is 18 gauge.

The only issue I could see using the larger wire (18 gauge) is that it wouldn't fit in the connector properly.

Hope that helps.

[tkammen]

Hi, I will be installing a 6 speed into my 92 soon but have some questions. I am using GD subframes and an R180 rear diff. Will my 04 STi driveshaft work with the 6 speed and R180 in the car? Someone told me I would need to extend the driveshaft by 2.5 inches. I don't understand why I would need to do that. Wouldn't it be the same length as a GD?

[mike-tracy]

Hi, I will be installing a 6 speed into my 92 soon but have some questions. I am using GD subframes and an R180 rear diff. Will my 04 STi driveshaft work with the 6 speed and R180 in the car? Someone told me I would need to extend the driveshaft by 2.5 inches. I don't understand why I would need to do that. Wouldn't it be the same length as a GD?

The automatic 1st gen legacy driveshaft fits perfectly with the 6mt. So long as you swap the flange from the existing r160 onto the new r180. Subaru made minor adjustments in length with each generation of cars. It corresponds more or less to the changing wheel bases between generations and models also.

[tkammen]

Alright. Once I get all the parts into the car I will measure what length driveshaft I need. In my GD WRX currently is a DSS Aluminum for a 6 Speed. I was hoping to reuse that on the Legacy.

[vtsportscar]

The 04 sti driveshaft with the rear section extended 2.5” fits in my 93 Legacy L with the 6spd, R180, gd cross-members. I’m interested to test fit the Outback auto driveshaft I have to see if the length is also correct for the 6spd and can work as a spare in a pinch if I swapped diff flanges. Sounds like a good project for the off season. Right now I’m just excited to have the old girl back up and race ready again! Been since March of 2018 she saw competition last.. Labor Day weekend trackcross will be her long awaited return

[Legacy777]

Yeah, let us know what you find out and good luck with the race!

[kleinkid]

Lower starter bolt. I have a 257 to put in my 94 ss with an 05 STi trans. Looking at the 257 block, the 6 spd flange, and comparing to my 2010 STi, it looks like won't have to drill and tap the trans, or drill lower bolt hole on starter out to 9/16. Correct?

[kleinkid]

I figured it out. I need two bolts and one is longer than the other. 800510060, 80210000. These bolts bolt the starter down and clamp the trans to the engine. These are two of the eight that bolt trans to engine.

[Legacy777]

Yup, as you found out if you use the newer eight bolt main engines you don't need to do anything with the trans.

I have thought about an EJ257 engine....but don't know if I can justify the money since we've got a lot of other expenses now.