Welcome to the North American Subaru Impreza Owners Club Friday March 29, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Subaru Conversions

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 06-04-2003, 04:28 PM   #1
serious
Scooby Specialist
 
Member#: 22879
Join Date: Aug 2002
Location: missoula , montana
Default wrx rear differential in a legacy?

Hi all, i'm wondering if the 02 wrx 3.90 differential will bolt right into my 96 legacy? I think i read somewhere i would need the axles too as there not the same? Would i need the hubs too or just the axles?
Anything else needed to convert?
Thanks
Brent
* Registered users of the site do not see these ads.
serious is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 06-04-2003, 05:34 PM   #2
Jaxx
Scooby Guru
 
Member#: 177
Join Date: Aug 1999
Chapter/Region: NWIC
Location: Austin, Texas, USA
Vehicle:
The 93 W/EJ20K-sold
Subaru-less :(

Default

just the axles .. but .. only the WRX wagon/legacy turbo/2000-2001RS axles wil fit as the WRX sedan are longer ....


although stimpy has come up with some findings that may contradict this

the diff from the manual WRX is not 3.9 it is 3.54
Jaxx is offline   Reply With Quote
Old 06-04-2003, 05:57 PM   #3
stimpy
Homicidal Maniac
Moderator
 
Member#: 1612
Join Date: Jun 2000
Location: Austin, TX
Vehicle:
2008 STI

Default

I don't know if it was an accident or what, but the front axles do not list lengths in the FSM; just the rears. Going by that logic, the didn't feel the need to specify the lengths since they would be the same. Diameters etc are still listed since they are different from the RS and the WRX. Seems really weird that the front axles would be the same length between sedan and wagon. One of these days I might call the dealership and have them run a part number check.

The lengths of the rear axles are explicitly mentioned in the FSM though. The rear axles are 5mm different between the sedan and wagon and 10mm different between left and right in the rear. You could actually use left hand rear sedan axle for the right hand rear wagon axle. I don't have the FSM for the RS to know if the axle length is the same between the wagon and the 2000-2001 RS. I would imagine they are the same though due to reports that the control arms are the same and since the crossmember (that the control arms mount to) will bolt right up to the GC chassis.

LSD axles are needed for a rear diff that has an LSD. Open diff axles are needed otherwise. Falling into the nether regions of unknown, this doesn't seem to apply 100% when we start talking about early '90's cars.

The outer spline count, located at the hub, for front and rear is the same throughout the years for fronts and rears individually. Your hubs will be fine, it is only the inner spline count that you should be concerned with. I need to finish up my spline count thread in the transmission forum and get it moved over here and made sticky or something.

[EDIT] And just to contradict Jaxx, the Legacy Turbo LSD uses different axles than that of the WRX/RS. I have no idea what the spline counts on those are.

-Jon

Last edited by stimpy; 06-04-2003 at 06:06 PM.
stimpy is offline   Reply With Quote
Old 06-04-2003, 06:48 PM   #4
ciper
Scooby Guru
 
Member#: 15543
Join Date: Feb 2002
Vehicle:
555 Having a Subaru
shop means too many cars

Default

Here is some more confusion.

Some rear axels are a "female" like the front on the inner join and use a pin to connect.
Others are a "male" connection on the inner joint and are held by a wire circlip

Some of the "female" axels have stubs that are basically bolted to the differential while others also use a wire circlip

Your best bet is to take the WRX differential apart and remove the LSD portion. Then try to install it into your original differential using the old ring. Since the axel stubs connect to the LSD you may have to mix and match parts (if its even possible).
ciper is offline   Reply With Quote
Old 06-05-2003, 12:29 AM   #5
Kha0S
Scooby Guru
 
Member#: 8808
Join Date: Jul 2001
Chapter/Region: NESIC
Location: WRJ, VT
Vehicle:
2011 WRX
DGM 5D

Default

WARNING:

The WRX rear differential is NOT a 3.90 ratio. It is a 3.545 ratio, due to the 1.1:1 center transfer ratio! The front diff is 3.90, center diff is 1.1:1, and the rear is 3.545:1.

You will annihilate your center diff if you put in a WRX LSD unit.

/Andrew
Kha0S is offline   Reply With Quote
Old 06-05-2003, 12:41 AM   #6
serious
Scooby Specialist
 
Member#: 22879
Join Date: Aug 2002
Location: missoula , montana
Default

Good thing i'm putting in a wrx transmission and engine too huh?
B
serious is offline   Reply With Quote
Old 06-05-2003, 08:14 AM   #7
Kha0S
Scooby Guru
 
Member#: 8808
Join Date: Jul 2001
Chapter/Region: NESIC
Location: WRJ, VT
Vehicle:
2011 WRX
DGM 5D

Default

Come now, don't give me the :monkey:.

Your original post stated bolting the 3.90 diff right into your 1996 Legacy. A lot of people make the mistake of that differential being a 3.90, and I don't want to see anybody on here munch their center diff just because Subaru picked a screwy center transfer ratio on the US WRX.

/Andrew
Kha0S is offline   Reply With Quote
Old 06-05-2003, 03:49 PM   #8
serious
Scooby Specialist
 
Member#: 22879
Join Date: Aug 2002
Location: missoula , montana
Default

Yeah, my bad on the center differential/ rear end ration. It is different. What i meant to say was installing a wrx rear differential and not the 3.90.
What's so bad about the munkey? He's not flipping you off or anything.
Brent
serious is offline   Reply With Quote
Old 06-05-2003, 03:52 PM   #9
Kha0S
Scooby Guru
 
Member#: 8808
Join Date: Jul 2001
Chapter/Region: NESIC
Location: WRJ, VT
Vehicle:
2011 WRX
DGM 5D

Default

Depends on the connotation... some people use the disco monkey as a negative comment.

Unfortunately, I don't have spline counts for the rear diff on those vehicles... I had my 4.111 rear diff modified with a 3.9 ring and pinion from an Outback Sport to do my conversion to the Legacy Turbo transmission... so I can't really help.

Good luck with it!

/Andrew
Kha0S is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
2002-2005 WRX Rear Differential R160 out of an 05 WRX Bugeyeballa MAIC Private Classifieds 5 12-04-2008 10:38 PM
sti rear differential in a 03 wrx? Waldorf Transmission (AT/MT) & Driveline 3 03-25-2008 07:50 PM
WTB - Rear Differential for 97 Legacy OB EricScott Private 'Wanted' Classifieds 5 04-10-2006 08:28 PM
WTB - Rear Differential for 97 Legacy OB EricScott Tri-State Area Private Classifieds 1 04-10-2006 07:34 AM
wrx rear differential/axles in a legacy? serious Legacy Forum 4 07-01-2003 10:33 PM

All times are GMT -4. The time now is 10:31 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.