Possible upgrades to 5-6-8 speed auto

[scottryana]

Brain is still turning, but in my searches I found this pretty cool document.

http://m.doc88.com/p-583712611999.html

It describes the A750F vs the A343F.

It says the size and length were kept the same, and that the power used at certain points is 12% less. In a drivetrain that losses 30+% of the engine's power, swapping an A750 would give you a nice feeling of increased power.

 

[cjmoon]

i ran into some threads while researching general control for my understanding of the a343f for my swap on Supra forums they push the limit more than Cruiser community with trying things and seeing what happens. If i have problems with my trans i'll be doing some more research for sure.

 

[scottryana]

The other thing for big torque would be that they uprated the A750F. If you use a shift kit and believe their claims to double the capacity that would be 618ft/lbs for the A343F and 736ft/lbs for the A750F.

I am surprised this hasn't been done. Same size, same bolt pattern, same transfer case, it has a separate TCU like the 80, might be as easy as depining the 80's connector and repining the 100 TCU. It might not but you never know. lol.

 

[yotaslave]

I thought the big issue was the extra electrical inputs required from the ecu? I would love to have one though! I would think a standalone tranny controller could run it much like the one used on the 6bt swaps.

 

[landtank]

what about the difference in the starter location? Or do you swap out the bellhousing?

 

[scottryana]

I would imagine swap the bell housing. The early 100's had the wrong starter location, but still used A343F's so I would think that the belhousing bolt pattern is the same on the transmission side.

 

[landtank]

Also, I thought the TCUs for the A343F was part of the ECU.

 

[scottryana]

Nope 2 separate boxes, at least they are in the 100 series with the A343F.

 

[landtank]

ya, but we are talking 80s. as far as I know the A442F(or whats in a 93/94) is a separate TCU and the A343F is integrated.

 

[scottryana]

Yeah except the important part is if the A750F is a separate box and if you can de-pin the 80's TCU/ECU and use those inputs on the A750 computer.

 

[S.CarolinaFZJ80]

Sub'd

 

[Delancy]

I am surprised this hasn't been done.....same transfer case

I'm surprised it hasn't been done FOR the transfer case options possible with the A750F.

 

[scottryana]

Yeah A750 is also used in 4runner, Tacoma, Tundra, and FJ Cruiser.

 

[tlin]

Interesting - not applicable to me but sub'd all the same.

 

[landtank]

Yeah except the important part is if the A750F is a separate box and if you can de-pin the 80's TCU/ECU and use those inputs on the A750 computer.

I guess I don't understand what you mean by "de-pin".

 

[scottryana]

Pull the wires that are transmission specific out of the connector that goes into the 80 series computer and either split their output into the 100 series TCU or if they are only for the transmission you could just find out what pins match on the 100 series connector and put them in that position.

Example:

Throttle position sensor - you know that is going to be needed by the ECU and TCU, you would find that wire, cut it and pin it to the new 100 series plug and the 80 series plug, the 80's computer would get the TPS input and the 100 series trans would also get the TPS input

Turbine Speed Sensor - is only a transmission function for speed of input shaft for torque converter lockup function you could de-pin this from the 80 series ECU and pin it on the correct pin on the 100 series TCU.

 

[landtank]

I thought that is what you meant and I can't see that working but haven't checked the wiring diagrams either.

On a side note. the last year truck that I can find a separate TCU for is the 1994 LC with the A442F.

Got a part number for the TCU that goes with this transmission?

 

[scottryana]

I know the 100 has one at least it did for the A343F, I used it in my 55, when I ran a 2UZ with A343F in it. I would have to do some digging. I wonder if the 100 series that kept the 1FZFE in other countries much past 1997 had the A750F behind them?

 

[OGBeno]

I know the 100 has one at least it did for the A343F, I used it in my 55, when I ran a 2UZ with A343F in it. I would have to do some digging. I wonder if the 100 series that kept the 1FZFE in other countries much past 1997 had the A750F behind them?

Negative. They never received an automatic five speed box. Only four speed.

Cool thread indeed though Ryan.

 

[LandCruiserPhil]

The 3.5 first is another place the 5speed shines