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
- - - - -

Swapping a manual to an automatic


  • Please log in to reply
10 replies to this topic

#1 BratWarrior

BratWarrior

    USMB Regular

  • Members
  • PipPipPip
  • 98 posts
  • Portland

Posted 31 January 2014 - 02:41 AM

Ok... don't kill me for asking this. I am thinking of swapping out the manual D/R tranny for an automatic on my new '84 hatch. This car is going to be my girlfriend's once my BRAT is back in commission and she has no interest in learning stick (this would be her first car). I'm assuming the swap would be straightforward (change tranny and shifter, remove clutch pedal, etc.). Has anyone tried this? Any info would be appreciated. It should be noted that the clutch needs to be replaced on this thing asap anyway. Thanks!



#2 BratRod

BratRod

    USMB is life!

  • Members
  • 504 posts
  • Dallas, Texas

Posted 31 January 2014 - 08:31 AM

You would need the flexplate, transmission cross member, wiring, the shifter, the plate the shifter mounts to, (requires cutting and welding in place) and I think there is a downshift switch on the pedal... Regardless of what it is. You need that. Need a 3.7 diff for the rear. And I remember reading somewhere that the trans tunnel is smaller on manual cars, which could make swapping an automatic a pain... Don't hold that to me, though. I don't think you have to switch the pedal box from manual to auto, but it would probably be better to have the bigger pedal if its her first car.

If you have a whole parts car; the swap shouldn't be that hard. Or maybe it is. I have an auto and manual brat, they're really similar as one would think.

#3 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 19,896 posts
  • WV

Posted 31 January 2014 - 09:05 AM

you'll be installing a 3AT i assume?

 

there's no (or limited) wiring, nor a TCU to deal with, so it's all mechanical and not electrical in nature.  that's a good thing.

 

reverse lights would need addressed since they're triggered differently between auto/manual.

 

center console and instrument cluster to clean things up. i've driven without an instrument cluster in numerous Subarus from the 80's to the 2000's so they're not necessary components.

 

ask someone about rear driveshaft - on 4EAT models the driveshafts are different lengths between manual and automatics.



#4 Gloyale

Gloyale

    It's a sickness

  • Members
  • 9,252 posts
  • Corvallis, OR PNW

Posted 31 January 2014 - 12:16 PM

You would need the flexplate, transmission cross member, wiring, the shifter, the plate the shifter mounts to, (requires cutting and welding in place) and I think there is a downshift switch on the pedal... Regardless of what it is. You need that. Need a 3.7 diff for the rear. And I remember reading somewhere that the trans tunnel is smaller on manual cars, which could make swapping an automatic a pain... Don't hold that to me, though. I don't think you have to switch the pedal box from manual to auto, but it would probably be better to have the bigger pedal if its her first car.

If you have a whole parts car; the swap shouldn't be that hard. Or maybe it is. I have an auto and manual brat, they're really similar as one would think.

 

He will not need a 3.7 rear diff unless it's an 83 or older 3at.

 

Trans tunnels are the same size.  It's the 4eat they enlarged the tunnel for......in 87 on EA82's

 

Rear crossmember for trans is easy to make out of flat steel.

 

Reverse lights would need wires from the engine bay run inside to the auto Shifter.

 

You'll need to run a vacuum line to the modulator.  I don't think there is a kickdown switch on the throttle....I think it's all vacuum controlled.....but I am not sure.  Certainly would drive fine without that.



#5 BratWarrior

BratWarrior

    USMB Regular

  • Members
  • PipPipPip
  • 98 posts
  • Portland

Posted 31 January 2014 - 02:14 PM

you'll be installing a 3AT i assume?

 

there's no (or limited) wiring, nor a TCU to deal with, so it's all mechanical and not electrical in nature.  that's a good thing.

 

reverse lights would need addressed since they're triggered differently between auto/manual.

 

center console and instrument cluster to clean things up. i've driven without an instrument cluster in numerous Subarus from the 80's to the 2000's so they're not necessary components.

 

ask someone about rear driveshaft - on 4EAT models the driveshafts are different lengths between manual and automatics.

 

I've read bad things about the 3AT on here. I think 4EAT would be the best choice. I would say that an instrument cluster is pretty important for a first time driver! 



#6 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 19,896 posts
  • WV

Posted 31 January 2014 - 05:37 PM

I've read bad things about the 3AT on here. I think 4EAT would be the best choice. I would say that an instrument cluster is pretty important for a first time driver! 

 

the 3AT sucks for some reasons but others familiar with subarus also say they are reliable if you take care of a  few minor issues - governor or something, i've never owned one but Johnfromky and others have said they can be decent for plain daily driver use.

 

swapping a 4EAT would require a complete wiring harness and grafting it into appropriate signals - at least the TPS and probably more.  it would substantially more work. if you're capable of doing a transmission swap then you're capable of also buying a car cheap needing work and fixing it - which would take less time probably. 

 

 

there is one simple 4EAT option that would be very easy but you may not like it.  if you swapped a 4EAT in there and ran it without any wiring or TCU it would function fine.  it would run in purely mechanical mode and always be in 3rd gear and always have the 4WD locked.  i've done it in XT6's with 6 cylinder engines and they have plenty grunt to make them fine as daily drivers even around here in the mountains.  slowest off the line obviously but not too bad.  an 80's 4 banger may not.  locked 4WD is easy - just splice into the one Duty c wiring and control it yourself - FWD or locked 4WD.

 

indeed i wasn't saying to run without a cluster!  that would be awful for anyone.  i was just saying it would at least be movable with an instrument cluster and driveable for testing/finishing up, not that you'd want to keep it that way in any case.  it is odd driving not knowing your speed or volts, or oil pressure or anything.

 

sometimes i like to know, with a project, what is going to get me on the road driving and what's going to hold it up.


Edited by grossgary, 31 January 2014 - 05:37 PM.


#7 rdweninger

rdweninger

    USMB Regular

  • Members
  • 476 posts
  • Tillamook, OR

Posted 31 January 2014 - 08:02 PM

Ok... don't kill me for presenting this option... but I just can't help myself.

Keep the stick shift and find a new girlfriend.   

Problem solved.



#8 mr sarcastic

mr sarcastic

    New User

  • Members
  • PipPipPip
  • 118 posts
  • 03839

Posted 01 February 2014 - 06:32 AM

That's seems easier. Or, negotiating something so she'll learn how to drive a manual. Both options sound easier then swapping the drivetrain.

#9 BratWarrior

BratWarrior

    USMB Regular

  • Members
  • PipPipPip
  • 98 posts
  • Portland

Posted 01 February 2014 - 04:13 PM

Ok... don't kill me for presenting this option... but I just can't help myself.

Keep the stick shift and find a new girlfriend.   

Problem solved.

HAHAHA! Nah, She's a keeper and helped me buy my BRAT and hatch. She's definitely a old school Subaru supporter. I'm thinking I might just do the clutch job and make her learn stick.



#10 mr sarcastic

mr sarcastic

    New User

  • Members
  • PipPipPip
  • 118 posts
  • 03839

Posted 01 February 2014 - 08:38 PM

It's something everyone should know how to do.

#11 wagonist

wagonist

    User Awaiting Email Confirmation

  • Members
  • 455 posts
  • Sydney, Australia

Posted 02 February 2014 - 06:43 PM

In terms of the instrument cluster, the only difference is the shifter position for the auto. Completely unnecessary, use your eyes & look at the gearstick.

 

I'm really surprised no one else has mentioned the neutral safety switch. This is so the car will only start when the auto is in neutral or park. VERY IMPORTANT

 

You'll need to interecept the starter motor wire from between the ignition switch & starter motor. I'm not sure where the switch is, but for the 3AT I'm guessing on the gearstick itself. If you've already got a 3AT gearstick, you'll see 2 wires that are thicker than the rest. Connect one to the ignition switch & the other to the starter motor.

 

You'll also need to run an illumination wire from the dashboard to the selector. Again, this is a safety item so you know which gear is being selected at night. If you want, run both so that this light dims with the rest of the dash, but it's not necessary.






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users