Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

Rear diff


  • Please log in to reply
8 replies to this topic

#1 [HTi]Johnson

[HTi]Johnson

    Head Trauma, inc.

  • Members
  • 1,512 posts
  • Coburg, Or.

Posted 15 December 2004 - 02:19 AM

I was thinking today, I have a 4psd d/r range tranny in my car, I looked at the rear diff and it has a 3.7 ratio sticker on it. Is it supposed to be 3.7 or 3.9, for that tranny?
Before, I had the Auto tranny in it, and in 4wd at 45mph i would get a humming from the rear. It doesn't do it now...with the 4psd in there...maybe that's why the automatic died?
Thanks.
[HTi]Johnson

#2 GLCraig

GLCraig

    Livin' the live

  • Members
  • 2,706 posts
  • LV, Washington

Posted 15 December 2004 - 02:31 AM

The correct rear diff for a d/r 4speed is a 3.9 and the correct rear diff for a EA81 4wd Auto is a 3.7; you may have a misslabled rear diff if you're not binding with the current setup.

#3 [HTi]Johnson

[HTi]Johnson

    Head Trauma, inc.

  • Members
  • 1,512 posts
  • Coburg, Or.

Posted 15 December 2004 - 10:27 AM

What do you mean by not binding?

#4 Sweet82

Sweet82

    Elite Master of the Subaru

  • Members
  • 3,266 posts
  • Salt Lake City

Posted 15 December 2004 - 10:46 AM

In 4wd your rear wheels are trying to pass the fronts if you have a D/R and a 3.7 diff :banghead:

You'd probably hear your drivetrain trying to compensate for the difference in speed. Churping rear wheels?

You may be able to jack the car up and see if the front and rear wheel move the same speed in 4wd. :confused:

#5 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 19,800 posts
  • WV

Posted 15 December 2004 - 01:23 PM

binding....in 4wd going around a turn on concrete...does it feel like itsbraking when your wheels are turned all the way?

#6 Numbchux

Numbchux

    EJ conversion addict

  • Members
  • 5,991 posts
  • Duluth, MN

Posted 15 December 2004 - 05:43 PM

binding....in 4wd going around a turn on concrete...does it feel like itsbraking when your wheels are turned all the way?


that's it, but if you've got the wrong diff in there, it'll do that when you're going straight

#7 garner

garner

    Brat Master Flash

  • Members
  • 689 posts
  • Vilas, NC

Posted 15 December 2004 - 06:08 PM

I was thinking today, I have a 4psd d/r range tranny in my car, I looked at the rear diff and it has a 3.7 ratio sticker on it. Is it supposed to be 3.7 or 3.9, for that tranny?
Before, I had the Auto tranny in it, and in 4wd at 45mph i would get a humming from the rear. It doesn't do it now...with the 4psd in there...maybe that's why the automatic died?
Thanks.
[HTi]Johnson


That tranny is definately 3.9 and that's the diff you need. I'm surprised something hasn't busted yet....

garner

#8 [HTi]Johnson

[HTi]Johnson

    Head Trauma, inc.

  • Members
  • 1,512 posts
  • Coburg, Or.

Posted 16 December 2004 - 12:00 AM

well, guess what I need to buy.

#9 garner

garner

    Brat Master Flash

  • Members
  • 689 posts
  • Vilas, NC

Posted 16 December 2004 - 01:10 AM

hti,

pm me. I have a spare 3.90 diff.

garner




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users