Log in

View Full Version : STI 6 speed for the 818 What is needed?



palomino
08-15-2017, 12:41 PM
I had this posted on the Ask a FFR Tech page but did not get any responses, so I will try here.
My WRX 5 speed is very broken (after 1,150 spirited miles) and I would like to replace with the STI 6 speed.
The 818 is an early one, chassis # 97 and has a WRX 2.0 from a '94 WRX.
I found a newly rebuilt 2007 6 speed but it doesn't have anything else, just the transmission.
What parts do I need from either Subaru or the local used parts place?
I am assuming inner CV joints and maybe clutch pressure plate and flywheel.
FFR has the adapter but will the axles work? Is there anything else I need?
Is there a thread in the STI trans installation? (I couldn't find any).

Would like to get back on the road ASAP and couldn't find clear info on the forums.

Thanks,
Pete

q4stix
08-15-2017, 01:23 PM
Do you mean '04 WRX instead of '94? I thought that only the early WRX 5 speeds had the stubs in the transmission but the later years had the stubs as part of the front axles. I have an 07 which now has a 6 speed and I don't remember having to swap the axles or have new CVs when I did it a few years back.

I also seem to remember that the WRX flywheel, clutch, and pressure plate will all work with the STI transmission but the reverse will not work because the STI clutch is about 1" larger in diameter so it hits the bellhousing. I did need to swap the clutch slave cylinder from a push to a pull type but I don't remember if that's based on the transmission or on the pressure plate configuration.

STiPWRD
08-15-2017, 01:53 PM
Here are a few links that may help:

http://thefactoryfiveforum.com/showthread.php?11695-who-will-be-the-first-to-try-putting-the-sti-6-speed-tran-in
http://thefactoryfiveforum.com/showthread.php?16920-STI-Six-speed-DCCD-2WD-Conversion-Issue
http://thefactoryfiveforum.com/showthread.php?15905-Chassis-111-2006-STi-with-Blouch-2-5XTR-First-Drive-Video

Depending on what year your donor spindles are, they may not work with the sti axles or 6 speed trans. For instance, wrx's typically use 24 spline shafts and sti's use 27 spline shafts.

palomino
08-15-2017, 02:42 PM
Sorry for the typo.
The spindles are 04 WRX. The STI trans is an 07.
Looks like I may also need the STI axles and rear spindles as well as the inner CV joints.