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
- - - - -

What is my gearbox ratio?


  • Please log in to reply
11 replies to this topic

#1 EA82Turbo

EA82Turbo

    USMB Regular

  • Members
  • PipPipPip
  • 90 posts
  • Nelson, New Zealand

Posted 29 June 2004 - 04:34 PM

Hi all :)

I have a ea81T engine but I don't think the gearbox is standard. The gearbox is 5 speed with 2wd, 4wd hi and 4wd low. Currently I have a 3.9:1 diff on it but are not sure if it is the right diff?

Would the car be drivable with the wrong diff?

How would I test the gearbox ratio?

Cheers

#2 Dr. RX

Dr. RX

    Elite Master of the Subaru

  • Members
  • 9,984 posts
  • Sammamish, WA

Posted 29 June 2004 - 07:48 PM

Pull the front axles, count the number of spline on the stub axle, 23 usually mean a N/A tranny with a 3.90 ratio, if the count is 25, it usually means it is a turbo tranny with a 3.70 ratio. Not 100% fool proof, but is right probably 99.9% of the time for a 5 speed D/R on-demand 4WD tranny

#3 EA82Turbo

EA82Turbo

    USMB Regular

  • Members
  • PipPipPip
  • 90 posts
  • Nelson, New Zealand

Posted 29 June 2004 - 07:51 PM

Thanks :)

So would the car be drivable with the wrong diff?

#4 WoodsWagon

WoodsWagon

    Formerly 91Loyale

  • Members
  • 3,945 posts
  • NH

Posted 29 June 2004 - 07:57 PM

In 2 wheel drive, yes. In 4 wheel drive, no. the rear differential just freewheels until you engage 4wd. One easy way to check is to jack up both wheels on one side of the car, put 2 chalk marks on the tires, both at the same place, put the car in 4wd and turn the wheels. If the chalk marks still match, the diffs are the same, if they don't, you need a new rear diff.

#5 EA82Turbo

EA82Turbo

    USMB Regular

  • Members
  • PipPipPip
  • 90 posts
  • Nelson, New Zealand

Posted 29 June 2004 - 07:59 PM

cheers :headbang:

#6 Dr. RX

Dr. RX

    Elite Master of the Subaru

  • Members
  • 9,984 posts
  • Sammamish, WA

Posted 29 June 2004 - 10:32 PM

Gee, if you can figure out what the tranny ratio is, and you can see the decal on the rear diff that tells you the ratio there, why would you have to do all that wheel spinning???

#7 XSNRG

XSNRG

    Elite Master of the Subaru

  • Members
  • 3,657 posts
  • Olympia

Posted 30 June 2004 - 08:15 AM

chalkmarks and jack stands are a lot easier than pulling an axle...:-)

#8 MilesFox

MilesFox

    Catch this Fox!

  • Members
  • 10,351 posts
  • Madison/Milwaukee, WI

Posted 30 June 2004 - 08:23 AM

the ea81 turbo was not available with the 4wd 5spd (not in the US anyway. )

you describe a dual range lever. there were part time dual range (23 spline) and full time dual range (RX)

but if its in an ea81 body, which used 23 solined axles, mos likely you have a part time 4wd dual range from a non turbo, which will have a 3.9 gear

go find soem sand or loose gravel, engece 4wd and see if she binds up or not

#9 MilesFox

MilesFox

    Catch this Fox!

  • Members
  • 10,351 posts
  • Madison/Milwaukee, WI

Posted 30 June 2004 - 10:50 AM

where did you get the car from? maybe we can trace it back to a usmb member as a previous owner?

#10 MorganM

MorganM

    Do you Subaru?

  • Members
  • 8,390 posts
  • TwinCities

Posted 30 June 2004 - 10:58 AM

Pull the VIN and call a stealership :drunk:

Unless the trans has been swaped ?

#11 Dr. RX

Dr. RX

    Elite Master of the Subaru

  • Members
  • 9,984 posts
  • Sammamish, WA

Posted 30 June 2004 - 01:25 PM

Chalk marks and jack stands won't give you the tranny ratio and that is what he is looking for. Pulling axles is easy if you know the trick, and since he wouldn't be completely pulling the axle, this won't be even easier.

Fox and Shadow, the 85 and 86 RXs had the part time 4WD trannies and 3.70 ratio, plus 25 spline stub axles, actually the Fulltime 4WD trannies didn't show up until the 87 1/2 model.

#12 WoodsWagon

WoodsWagon

    Formerly 91Loyale

  • Members
  • 3,945 posts
  • NH

Posted 30 June 2004 - 06:48 PM

My test wll tell you if the front and rear diffs match though, and thats what he cares about. My bets are on the 3.9, mostly because they're more common, and the prevous owner would have (or should have) alerted him if he had swapped in a 3.7 tranny, but not the rear diff.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users