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swapping 2wd 4AT into 3AT car???


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16 replies to this topic

#1 thealleyboy

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Posted 16 January 2007 - 12:18 PM

Looks like the A/T 3speed in my 85 2wd GL is finally hosed. Tried fooling around with the governor, mudulator, etc and it's not happenin'...

I'm not a big fan of A/T's (or 2wd's) and I'm trying to decide what to do with this car. It's in fair-good condition overall with low miles. Not quite nice enuff to do a 4wd conversion. I have access to a manual 2wd 5 speed, and I'm not even sure that an AT to manual conversion is worth it for me.

I do have a 2wd 4AT that came out of an 89 GL 10 turbo, that I'm considering for this car. If it will work, it would be an easy fix, and maybe even perform better. What I'm not sure about is if the ECU will have to be changed too. I thought I remembered reading a post where someone said that swap was too big of a jump in a carbed EA82. Something to the effect that turbo trannies needed the computer controls to shift properly.

Any thoughts/opinions would be appreciated. I think A/T's suck, and know very little about them...

John

#2 mikeshoup

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Posted 16 January 2007 - 12:21 PM

In 88 (or was it 87?) there was a change to the transmission tunnel to fit the 4EAT under the car. The 4EAT is significantly larger than the 3AT.

If you could physically fit it under you 85, you still need the TCU and wiring harness for the 4EAT as well as the shifter console and stuff. A 5MT conversion would actually be easier :-\

#3 baccaruda

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Posted 16 January 2007 - 12:26 PM

yeah, sounds more like a motor donor to me..

#4 NorthWet

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Posted 16 January 2007 - 12:35 PM

...What I'm not sure about is if the ECU will have to be changed too...

On the New-Gens, there is an Atmospheric Pressure Sensor built into the ECU that sends a hi/low signal to the TCU; someone (nipper???) recently said that this signal was not used in the Old-Gen ECU/TCU so may be a non-issue. The only other known-to-me signal would be the Vehicle-Speed-Sensor (VSS) that all of the EA82s have.

Sounds to me like a lot of work. Do you have access to the 4EAT's axles? All of the shifter mechanism?

#5 GeneralDisorder

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Posted 16 January 2007 - 01:24 PM

2WD 5 speed swap is FAR easier due to the wireing issues with the 4EAT. Plus the 4EAT probably uses 25 spline "turbo" axles so you would end up swapping those too...... manual is way easier - no wireing, no axle problems, no tranny cooling lines, etc, etc. Should just bolt right in - you'll need the manual cross-member and linkages plus the flywheel/clutch setup.

GD

#6 thealleyboy

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Posted 16 January 2007 - 03:44 PM

Hey, thanks for all the great replies!!

Sounds like the consensus is for swapping in that 5 speed (which is fine with me).

Initially, I was reluctant to convert from a 2wd At to a 2wd 5 speed. I mean, if I'm going to convert, why not go all the way and make it a 4wd???

But now I'm thinking the 2wd5 is a relatively easy swap - considering the axles, and electrical work involved. I have some better "projects" to work on, but these cars are getting scarce around here, so I hate to scrap an otherwise solid EA82.

thanks again, John

#7 hatchsub

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Posted 16 January 2007 - 04:30 PM

I did a write up about the swap on an EA81. Its in the USRM. Some aspects are slightly different but for the most part its the same procedure. Someone else can chim in with the differences.

#8 Gloyale

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Posted 16 January 2007 - 04:43 PM

Looks like the A/T 3speed in my 85 2wd GL is finally hosed. Tried fooling around with the governor, mudulator, etc and it's not happenin'...

I'm not a big fan of A/T's (or 2wd's) and I'm trying to decide what to do with this car. It's in fair-good condition overall with low miles. Not quite nice enuff to do a 4wd conversion. I have access to a manual 2wd 5 speed, and I'm not even sure that an AT to manual conversion is worth it for me.

I do have a 2wd 4AT that came out of an 89 GL 10 turbo, that I'm considering for this car. If it will work, it would be an easy fix, and maybe even perform better. What I'm not sure about is if the ECU will have to be changed too. I thought I remembered reading a post where someone said that swap was too big of a jump in a carbed EA82. Something to the effect that turbo trannies needed the computer controls to shift properly.

Any thoughts/opinions would be appreciated. I think A/T's suck, and know very little about them...

John



My 89 FSM does not list any 2WD 4eats. The early 4eats were all the "fullTime" 4wd models. Are you dead sure? My 87, 88, and 89 FSM's say the same. So for a tranny that supposedly doesn't exist, I don't what to tell you about the swap. I have a 2wd 3speed from a 88 GL-10. I would love to get it to someone who will use it. It would be a direct fit, I'll include the Torque converter and flex plate. The turbo ones are slighlty tougher and have a higher stall on the TC.

#9 john in KY

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Posted 16 January 2007 - 05:57 PM

My 89 FSM does not list any 2WD 4eats. The early 4eats were all the "fullTime" 4wd models. Are you dead sure? My 87, 88, and 89 FSM's say the same. So for a tranny that supposedly doesn't exist, I don't what to tell you about the swap. I have a 2wd 3speed from a 88 GL-10. I would love to get it to someone who will use it. It would be a direct fit, I'll include the Torque converter and flex plate. The turbo ones are slighlty tougher and have a higher stall on the TC.



Bought the engine and transmission from either an 88 or 89 XT years ago and it was the FWD 4EAT. My 88 XT6 also has the FWD version.

#10 mikeshoup

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Posted 16 January 2007 - 06:09 PM

My 89 FSM does not list any 2WD 4eats. The early 4eats were all the "fullTime" 4wd models. Are you dead sure? My 87, 88, and 89 FSM's say the same. So for a tranny that supposedly doesn't exist, I don't what to tell you about the swap. I have a 2wd 3speed from a 88 GL-10. I would love to get it to someone who will use it. It would be a direct fit, I'll include the Torque converter and flex plate. The turbo ones are slighlty tougher and have a higher stall on the TC.

Never say never. XT and XT6 had FWD 4EAT. And it would also have been available on EJs.

#11 thealleyboy

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Posted 16 January 2007 - 10:02 PM

Never say never. XT and XT6 had FWD 4EAT. And it would also have been available on EJs.


I'll contact Sube of America, and have them look up the VIN. I'm 90% certain that it is the 4AT. It came out of a somewhat rare "highline" model (89 Turbo GL10 Touring Wagon), and the unit is physically larger than the 3 speed AT. Also, if I recall, the shifter had the extra gear. But I'll check it out to be 100% certain.

As far as the 85, I'm on the fence about doing the 5 speed. If the trannie is as rare as it appears to be, the 4AT swap is probably waste on this particular car. I ran the motor pretty hard in 1st gear (when it wasn't shifting up), and it's ticking louder than it normally did. It never "redlined", but I'm not as confident about the motor as I was before the trannie hung up on me. If I didn't have so many other "projects" in the works, it would be a no brainer. But It's kinda hard to get excited about an 85 2wd 5 speed in FC, if ya know what I'm sayin'.

On the plus side, there's not a lot of 85's around here in "FC"...

John





#12 mikeshoup

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Posted 16 January 2007 - 10:18 PM

I'll contact Sube of America, and have them look up the VIN. I'm 90% certain that it is the 4AT. It came out of a somewhat rare "highline" model (89 Turbo GL10 Touring Wagon), and the unit is physically larger than the 3 speed AT. Also, if I recall, the shifter had the extra gear. But I'll check it out to be 100% certain.

Never doubted you that it was a 4EAT. The fact that it is physically bigger is a dead give away right there.

Should be plenty of 5spd FWDs available in the Junkyards. They made FWD soobs all the way until 1994. That gives you any FWD 5spd from a GL/Loyale from 1985 to 1994 that will fit.

#13 Gloyale

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Posted 17 January 2007 - 09:45 AM

Well, people are saying some XT's had a fwd 4spd. But the FSM for the 87,88,and 89 says that that Automatic, fwd, GL-10's had 3spds. You said yours came from a GL-10. I'll believe anything is possible when it comes to Soobs. I am just trying to be constructive. Does the shifter go D-3-2(won't have the 1), or D-2-1? Are you sure someone didn't swap the tranny into the GL-10 from something else? At any rate I've got a good working 3spd fwd that i would part with for near nothing:)

#14 john in KY

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Posted 17 January 2007 - 10:14 PM

The key here the donor car was a GL-10 TURBO. Subaru didn't use the 3-speed in the 88 and 89 GL-10 TURBOS. My old 90 Loyale with TURBO, last year for the turbo, had the 4EAT.

#15 mikeshoup

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Posted 18 January 2007 - 12:09 AM

Well, people are saying some XT's had a fwd 4spd. But the FSM for the 87,88,and 89 says that that Automatic, fwd, GL-10's had 3spds. You said yours came from a GL-10. I'll believe anything is possible when it comes to Soobs. I am just trying to be constructive. Does the shifter go D-3-2(won't have the 1), or D-2-1? Are you sure someone didn't swap the tranny into the GL-10 from something else? At any rate I've got a good working 3spd fwd that i would part with for near nothing:)

Your 87,88 and 89 FSMs do NOT cover XTs.

In 87 and after, the XT has its own FSM

#16 baccaruda

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Posted 18 January 2007 - 01:28 AM

John (alleyboy), are you interested in ever running the car as a 4WD? You can block off the driveshaft output of the 4WD with a CV boot w/small end plugged if you want to do just half the conversion now... no gear oil loss that way.

#17 Gloyale

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Posted 18 January 2007 - 09:50 AM

The key here the donor car was a GL-10 TURBO. Subaru didn't use the 3-speed in the 88 and 89 GL-10 TURBOS. My old 90 Loyale with TURBO, last year for the turbo, had the 4EAT.


The 3spd auto I have in my garage came out of an '88 GL-10 Turbo. I pulled it with my own two hands. FSM's for 88 and 89 DO NOT LIST a 4eat for Front wheel drive. As I said anything is possible but just cause it was a GL-10 doesn't mean it had a 4spd.

Your 87,88 and 89 FSMs do NOT cover XTs.

In 87 and after, the XT has its own FSM


I am aware and actually have the 87 XT FSM as well. But The Alleyboy said his donor car was a GL-10, not an XT. so that is not really relavant. It may have been optional in the gl-10s and not covered in the book. I am just stating info from one of the best sources (FSMs) available to us here on USMB. Not claiming it to be the end all to the topic. I am just saying he has to be sure he double checks and knows what he's got.




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