Can I suggest a new sticky?

[hybrid gti 2]

I found that there are questions as to what diff is what ratio and year. As well as oem diff type.

I found a r180 for cheap when I looked it up some stupid person put 08+ was 3.9. It's not it actually 3.54. So now I have a diff I can't use for my project.

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[snow_bound26]

+1

Sucks that people don't know that final drive and diff gearing can be different.

[Unabomber]

Love to have one but we'd all have to contribute, here's what I have. I just researched all the WRX drive ratios and these are 99% legit from 2002 to present. Everything else is suspect.




Found this info on legacygt.com regarding the markings on the diff carrier, as it relates to final drive and the type of differential installed.
Unless the carrier has rusted over too much, you will find one of the following codes (2 uppercase letters) painted in white on the diff carrier.
Code---Reduction gear ratio---LSD
CD --- 4.444 --- Viscous
CF --- 4.444 --- Viscous
EW --- 3.900 --- Viscous
HY --- 3.545 --- Torsen
JE --- 4.111 --- Viscous
T1 --- 3.900 --- None
T2 --- 4.111 --- None
TP --- 4.444 --- None
XJ --- 4.111 --- None
XU --- 3.272 --- Viscous
XZ --- 3.083 --- Viscous


WRX transmission (2002-2005)
WRX FD 3.90
(Front 3.9 center 1.1 rear 3.545)

WRX transmission (2005-2006)
WRX FD 3.70
(Front 3.70 center 1.0 rear 3.70)

WRX transmission (2007-2014)
WRX FD 3.90
(Front 3.9 center 1.1 rear 3.545)

WRX transmission (2015+)
WRX FD 4.11
(Front 4.11 center 1.0 rear 4.11)

FXT transmission
FXT FD 4.444
(Front 4.44 center 1.0 rear 4.44)

Legacy GT transmission
Legacy GT FD 4.11
(Front 4.11 center 1.0 rear 4.11)

Outback XT
XT FD 4.444
(Front 4.44 center 1.0 rear 4.44)

STi transmission
STi (USDM) FD 3.90
(Front 3.90 center 1.0 rear 3.90)



Please use the above as a copy/paste then change as you find info!

[T-37]

The Rallispec list is pretty comprehensive if you can get the part number off of the transmission you're buying. It tells you final drive and transfer ratio.

https://www.rallispec.com/downloads/...art_Public.pdf

edit: but it only goes up to ~2011 it seems

[JarHarms]

Originally Posted by Unabomber

STi transmission
STi (USDM) FD 3.90
(Front 3.90 center 1.0 rear 3.90)
Please use the above as a copy/paste then change as you find info!

STi 6MT transmission
(2004-2005) STi (USDM) FD 3.900
(Front 3.900 *center 1.00 rear 3.900)

(2006-2007) STi (USDM) FD 3.900
(Front 3.900 *center 1.10 rear 3.545)

(2008-2009) STi (USDM) FD 3.900
(Front 3.900 *center 1.10 rear 3.545) - I am pretty sure the Ralispec chart having the TR at 1.103 is a typo

(2010+) STi (USDM) - I am less familiar with the newer MYs but from what I understand they are have same specs as 2008-2009. At least of the specs we are outlining here.

*"center" is actually the transfer gears ratio, not the Cdiff itself