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1985 brat transmission swap


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Auto or manual?

 

Many transmissions will "fit" depending on how much work you want to do. I am in the process of fitting a 5 speed dual range transmission into my '86 Brat. It required a new "kit" from Jerry (Bratsrus) a lengthened driveshaft and different clutch. I believe an EJ series transmission would require even more.

 

How much work are you willing to put into it?

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An '85 Brat does not have a 5 speed stock - never happened. It would be a 4 speed if anything. Or it's already been swapped.

 

Automatic tranny swap would be a nightmare and would ruin the collectible value of the Brat. No one wants an auto in them.

 

Put in a 5 speed D/R - you won't regret that upgrade.

 

GD

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what would be so hard about swapping it for an automatic?
Part of the difficulty would be that I've not heard of anyone doing that with a Brat, so you'd be alone in exploring what needed to be done. That being said, an approach to that would be to find a turbo brat at a junkyard and use parts from it. Turbo brats (extremely rare) only came stock as an automatic and would make the conversion easier if the parts were good or repairable.
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The 3AT (3 speed automatic) that would be the obvious choice (since Brat's indeed came stock with these in automatic config) is a big pile of crap. That's one good reason not to.

 

The transmission tunnel sheet metal is physically different and larger on automatics so either the Brat would have to be lifted or have the tunnel beat out or modified to clear the auto.....

 

You would need:

 

1. Flexplate and torque converter

2. Transmission

3. Rear driveline

4. Rear differential

5. Transmission x-member and front suspension radius rod plates

6. Pedal assembly

7. Shifter assembly and all interior consoles

8. Vacuum system for the modulator.....

 

I'm probably forgetting some stuff since as Ed mentioned this is not a common swap - people go the other way because the automatic's are junk and tend to die. The later 4EAT is electronic and won't work on a car that doesn't have fuel injection as the TCU requires signals from some of the FI sensors like the TPS.

 

Most of those parts other than the tranny and rear diff would need to come from a 4WD automatic EA81 - 81 to 84 wagon/sedan/coupe or 81 to 87 Brat or 81 to 89 Hatchback..... the tranny and diff could come from any 3AT 4WD car including the EA82's made till '94.

 

GD

Edited by GeneralDisorder
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EA81 + 3AT

 

MyCarWCSS10.jpg

 

 

They aren't THAT bad, especially if it's not gonna be hard core wheeled, just driven in snow. The 3ATs near instant pushbutton engagement (electrically switched hydraulic) is perfect for areas of alternately snow and clear roads encountered in places other than the PNW.

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They aren't THAT bad.

 

It's not the functionality that's the problem - when they *work* they are fine. It's when they *stop* working that the problems start. And this tends to be somewhere before 200k miles - often quite a bit before. They have a bad tendacy to lose all their forward gears (only work in reverse) or to develop a problem where the governor drive gear eats the governor driven gear - resulting it repeated destruction of governors. This was so common a few years back (before they were all crushed :rolleyes:) that we had a special term for this behavior - we called it "apple cored governor syndrome". :-\

 

These days the 3AT 4WD trannys are getting scarce because they have simply all failed and been crushed..... but even though it's a Subaru part you won't see me losing much sleep over the loss of the 3AT :lol:. The 4EAT is an awesome transmission by comparison but as I mentioned it is not suited to an install in anything that's not also fuel injected.

 

GD

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nissan used a transmission made by subaru with an external transfer caser that is auto. if you want an auto that would be a good choice though the conversion would be very hard but if your wanting something auto and are willing to put out that much work its good to have something a little more fail proof.

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nissan used a transmission made by subaru with an external transfer caser that is auto.

 

Subaru automatic transmissions of the vintage being discussed here were made by JATCO which is now a subsidiary of Nissan. The 4EAT was built by Subaru but based on a JATCO design. I highly doubt that anything used by Nissan was actually built by Subaru - most likely it was a Jatco transmission and the Subaru one's just look similar since they were all based on similar designs....

 

*edit* - as found on Wikipedia: "The Ford Motor Company also uses a transmission on some Ford, Kia Motors, Mercury, and Mazda products called the F-4EAT, which shares some similarities with the Subaru, since they are both manufactured by Jatco. The Nissan Pathfinder has also used this transmission in the past with an external transfer case attached."

 

Made by Jatco - and not in any way compatible with a Subaru - most especially it would not share a compatible bell-housing.

 

GD

Edited by GeneralDisorder
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OT: It is common to use core designs for different applications. The 4EAT is also known as the R4AX-EL and EC8. The R4AX-EL core is used by Nissan and others. The 3AT uses an M41/M41A core design that was also used by at least Nissan.

 

The OP might have a good reason for wanting an automatic. For instance, due to joint issues, my wife finds it painful to drive a manual transmission in town.

 

Other than the truly poor governor design of the 3AT/M41, it is not that bad of an automatic. Very few automatics seem to last 200K, so the inability of the 3AT to make it that far is only bad in light of the general longevity of the rest of the drivetrain.

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With respect to GD, the 3at was an ok trans if properly maintained. I currently have 2 running, one in a Brat and one in a Turbo coupe. I have rebuilt these transmissions with good success but kits have dried up and parts are only available individually. The biggest thing is to keep the 2-3 band adjusted correctly, keep it cool and change fluid about every 20k,

 

If you can find an 82-84 sedan, coupe, or wagon or any Brat ( we tend to hang on to them ) with a complete setup that has a good trans you will have everything you need to change over.

 

After the snow is gone next spring I am going to start my next project. 84 turbo coupe ( no engine or trans ) which will get an EJ with 4eat installed and will let you know how hard it really is.

 

I am in the same situation as far as needing an auto trans. My wife because of physical disabilities can't drive anything else.

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I completely understand - if you can rebuild them and have no problem with the maintenance needs of them then they are *ok* transmissions - in the scheme of things they are a lot better than most american and a lot of other Japanese transmissions. 200k is not unusual to see on one.

 

I just think that putting in a used one (especially into a Brat which will devalue it) is a mistake. A Brat that is already a manual should be left a manual. What people do to the other body styles is not as much of a concern because they are (basically) worthless except as transportation. With excelent condtion gen 2 Brat's commanding up near $10k now it seems an unwise move.

 

GD

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But GD, The percentage of americans who cant drive a stick is on the fast rise!:lol:

 

Everyday I see more and more people with a phone and latte in hand on the highway. Almost daily I see someone reading a book, and two to three times daily, someone painting a masterpiece, on their face!:lol:(Even though its against the law.)

They wouldn't do that in a manual.

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They wouldn't do that in a manual.

 

I can talk on the phone, eat, smoke a cigar, AND drive a stick. :lol:

 

I have not mastered smoking my pipe while driving a stick - that's still a few years off I would imagine. Either that or I need to start driving my "old codger" truck with the 4 speed w/granny - 35 MPH and you are in 4th from then on so it might as well be an auto. I think that's how all the old pipe-smokers do it :rolleyes:.

 

GD

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I can talk on the phone, eat, smoke a cigar, AND drive a stick. :lol:

 

I have not mastered smoking my pipe while driving a stick - that's still a few years off I would imagine. Either that or I need to start driving my "old codger" truck with the 4 speed w/granny - 35 MPH and you are in 4th from then on so it might as well be an auto. I think that's how all the old pipe-smokers do it :rolleyes:.

 

GD

 

Lolz. I saw Yo'j's post, and I was just about to post in here and say that I've witnessed you talk on the phone, eat, smoke a cigar, and drive a stick. I scrolled a little further, and you beat me to it.

 

Jacob

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