Can anyone school me in the 4m40 automatic?

Picked up a second gen swb wide pajero originally a 4d56, was poorly swapped to a 4m40 do to a cracked block on the 56.

From what I understand it has a V4AW3 ? At least they did in 1994. This one has a waffle like casting on the top.

So, they had no computer and right now, it literally has a 3 position switch to shift first second third.. I basically bought this because I wanted a 4d56 to [put into my first gen 4 door im building.

I'm wondering about getting that transmission to run. I can source a auto computer from the uk, and I did manage to find a wiring diagram, but I really have no idea how these automatics work.

I guess im asking how feasible is it going to be to run this automatic in a gen 1?
 

plh

Explorer
I do not believe that an automatic transmission that bolts up to a 4m40 will also bolt up to a 4d56 unless the bellhousing is swapped. I also don't know if there is a bellhousing available to swap a 4d56 to a V4AW3. V4AW2 (aka: KM148, AW372, AW372L) is possible. A V4AW2 is cable shifted basically.
 
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JamesW

Adventurer
Yes the 2.8 and 2.5 have different bellhousings, and they're physically bigger on the 2.8. There's a small bit of a computer controlling the auto box on a 2.8, I think it's up in the fuse box area. I have one that I can check for you if you want

Sent from my ONEPLUS A6003 using Tapatalk
 

Toasty

Looking for that thing i just had in my hand...
I still think you have a Mitsu automatic, what is the vin number on the bottom of the block say? That will tell us what you've got and what the engine came out of
 
Yes the 2.8 and 2.5 have different bellhousings, and they're physically bigger on the 2.8. There's a small bit of a computer controlling the auto box on a 2.8, I think it's up in the fuse box area. I have one that I can check for you if you want

Sent from my ONEPLUS A6003 using Tapatalk


that would be great, trying to figure out which computer to use.

I'm hoping I can get a computer from the uk and wire it up to my first gen.

I'm not quite sure what all the computer uses for shifting though.

Does anyone know if they used the same trans for the entire life of the 4m40?
 

Toasty

Looking for that thing i just had in my hand...
hmm i think I have narrowed it down to a v4a51 transmission. Not sure if its from a pajero or delica

So, if you have the PCM that came from the 4M40 donor vehicle (assuming it wasn't scrapped in favor of the 4D56 ECU running the 4M40) you likely just need the harness branch to the V4A51 or V5A51 and Bob's your uncle. The mechanical diesel computers don't really care which engine they're running HOWEVER I'm betting the late Gen 2's with the Mitsubishi automatic transmissions had a PCM like the Sports and Gen 3's with those transmissions did.
 
Little update. I figured out where the engine set came from. Of all things, It's from a type 73 mitsubishi 1/2 ton light truck. Basically their military rig. That explained the 24v alternator. Looking at the specs. It seems it's a 4 speed so im guessing it would be the v4a51

I do believe some american vehicles came with that? basically the waffle cast 4 speed version of the v5a51 I guess. Hopefully I can source a computer off a usdm vehicle and see if I can get this transmission working.

Interesting enough, the type 73 had p n d 3 2 1 instead of the standard p n d 2 1

It also seems usdm montero sports with the transmission have the trans computer integrated into the ecm. So now im back to the drawing board on how to run this stupid thing. I do have a v4aw3 computer from a 1996 challenger 2.8. Maybe I can actually use that computer to run the v4a51
 
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plh

Explorer
I do have a v4aw3 computer from a 1996 challenger 2.8. Maybe I can actually use that computer to run the v4a51

I'd be surprised if these ECUs would swap. v4aw3 is an Aisin Warner (Toyota origination) built transmission, v4a51 is a Jatco (Nissan origination) built transmission.
 
yeah, im grasping at straws at this point. Seems like its almost pointless trying to run this transmission, unless maybe I can find a aftermarket transmission controller.
 

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