Replacing 5mt with 4EAT?

Flywheel, Clutch, Transmission, Axles, etc...

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douglas vincent
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Replacing 5mt with 4EAT?

Post by douglas vincent »

So, if I bust another tranny (will be the 4th), I am thinking of swapping to a 4EAT with high stall TC.

Question.

Do I have to get a auto tranny computer/controller to make it work? Or will it work "ok" without the computer. Can I just change gears manually?

Thanks
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Post by ericem »

I believe there are still solenoids which need to be powered. When I unplugged my tranny computer on my transmission and shifted to 1st was stuck in either 3rd or 4th.
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Post by AWD_addict »

The E in 4EAT is "electronic", so I bet you need a TCU.

I still have 2 TCUs for sale. :wink:
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Post by PhyrraM »

If you can figure out what solinoid does what, you can prolly accomplish gear changes with switches.

Most modern automatics have a line pressure solinoid. This is a duty cycle device. You would need to send it some type of PWM circuit to vary the line pressure. Basically the same would be needed to drive the AWD solinoid also.


Time to look for a good deal on a six-speed?
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Post by douglas vincent »

Rather go dogbox than 6 speed.... Hell, custom manual 4 speed to 130 mph would make me happy!
Reddevil, Awaiting new heart, will it ever happen?
1990 wagon, EJ25 12.3 @ 116.5 FAST Family wagon getting new motor soon
1992 wagon, wifes daily, high compression
1992 Touring wagon, should I keep it?
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Post by PhyrraM »

Why? Not arguing, just curious as I may have to make a similier decsion at some point.

I figure a 'bargan' six speed and a dogbox would be about the same cost (unless you can do the labor on the dogbox yourself).

The six speed would have stock levels of shifting convience, but the dogbox would be about 75 pounds lighter.
'93 Winestone SS Auto, '91 Pearl White SS.
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'94 FWD and '95 AWD Laguna Blue SVXs.
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evolutionmovement
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Post by evolutionmovement »

Dog box is stronger, lighter, has ratio choices, and there are no syncros to beat up power shifting. Sucks as a daily, but it doesn't matter with a race car.
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Post by Subtle »

Douglas

I have changed my built 4eat.

The idiots at Mr. Lube on a regular oil change went and drained the front diff and didn't refill it. It soon failed and I'll be getting some money out of them.

Got a complete tranny for $900. --the quote on a new diff was around $2000. Upon inspection, my tranny with two years on the build showed no wear.

However, the launch I can get out of the high-stall converter has always been too tempting and it has always whined a little. So I'm running the stock torque converter.

Maybe, after many decades I'm finally maturing----the high-stall is for sale.

I've bought stuff from Saltair and over the last few years they have been reliable and on this tranny said that it had 150,000 klicks on it. Over the past two weeks of hard use the front diff has been fine.

One would assume that the rest of the tranny is also fine.

It is for sale as well.

Also have the push-button box that directly controls the shifts---with this a tcu is not needed---never installed it.

For my raves about a built 4eat the above sticky pretty well covers it.
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Post by Legacy777 »

You really should have the TCU. There may be ways around it, but unless you're just drag racing it....even then, there's a decent chance of messing things up with too much line pressure. Also, you need the TCU to control the duty c solenoid.
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Post by SemperGuard »

Unless you're planning on doing a LOT of reverse engineering you need a TCU. There are like 40 wires in the whole thing. Some you could leave out. And you could in theory do this: http://bbs.legacycentral.org/viewtopic. ... ght=lockup
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Post by Subtle »

The shifter box is designed to replace the tcu, and the instal only involves a few wires. :-)
Subtle (normally aspirated engines suck):
05 Legacy GT Wagon with Cobb chip.
62 Alfa Romeo Spider- had a 1.6 L with 80 hp, now 2 L with 160 torque. Curb weight 2050 lbs.
93 Leg Twgn fmic, vf34, etc. ((sold))
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Post by thehookeup »

doug, i got a extra 4eat and computer if your interested. could be interesting i would consider it.
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Post by Subtle »

Have posted in the For Sale:

Shifter Control Box

High-stall Converter

Stock 4eat, without the front diff.
Subtle (normally aspirated engines suck):
05 Legacy GT Wagon with Cobb chip.
62 Alfa Romeo Spider- had a 1.6 L with 80 hp, now 2 L with 160 torque. Curb weight 2050 lbs.
93 Leg Twgn fmic, vf34, etc. ((sold))
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