A750F in 80-Series with 1FZ-FE

[FJ55luvr]

I have been pondering this and have seen the threads suggesting it will probably bolt up but getting it electrically hooked up would be a nightmare.

The reason I'd like to do this is to have a lower 1st and a higher overdrive. Here are the ratios of the A343F and A750F:

A343F
2.80
1.531
1.0
0.75
NA

A750F
3.52
2.042
1.40
1.0
0.716

I think it would improve mileage and be a better off-roader.

My guess is it bolts up b/c the 2UZ-FE had both transmissions bolted up and the 1FZ-FE also bolts to the A343F. And I believe both the transmissions bolt up to the HF2A(V) transfer case.

As far as the transmission ECU, couldn't one covert it to be a manually-controlled automatic, or manumatic as this guy put it?

And before anyone says, "just drop the 2UZ-FE into your 80" or some variant of that, I don't want to do that. I like my 1FZ and I'm keeping it.

What do you guys think?

 

[fe sus]

I think you should do it and take lots of pictures.

 

[Bjohnston115]

Are you saying the 343 doesn't have OD? It def does and it's close to .71 for sure. I'm more familiar with the 440 and 442 and I know people have swapped in the aw450 for the same reason you are doing, the lower first. You also get a nice pto with the 450.

 

[FJ55luvr]

No you are right. I'm new to postings and the first post was an absolute mess. I'll edit right away.

 

[bignasty]

Would an ECU from a manual trans equipped or a hydraulic type trans work? You might not have the OBII stuff but who cares about that.

 

[alia176]

I need some education on the electronic part of this swap. Does the A750F need extra ECU signals that the A343F equipped vehicle does NOT provide? Does the 100 series operate the A750F with a dedicated TCU or is it part of the ECU?

 

[Delancy]

Jowett would be an excellent resource on this. I know he's been instrumental in a few swaps and may have figured out.

 

[Buckru]

I read a swap Jowett did with the tcase out of an 80 or 100 into his new tundra. Very impressive work.

Buck

 

[FJ55luvr]

Would an ECU from a manual trans equipped or a hydraulic type trans work? You might not have the OBII stuff but who cares about that.

According to https://forum.ih8mud.com/80-series-tech/228787-a750f-5speed-slush-box.html#post3445591 "I was told the A750F tranny was controlled by the main ECU and uses sensors such as speed, TPS and APPS. I don't think the 80 even has an Accelerator Pedal Position Sensor, right."

More quotes from that same thread:

"The simple way to wire this up is to include the whole harness from the donor vehicle, including the V-8 motor part of the harness"

"if I had to mess with the whole harness and ECU then it is no longer a "simple" task from what it appears"

Then the thread stops. That's why I was thinking of making it a manumatic to not deal with all that. It's not a lot of work to shift an automatic manually, in fact the claims are that you can get better mileage that way.

 

[rove_mcanus]

The ideas on the ecomodder link will work, however without creating your own ecu, the basic setup of controlling the solenoids in the transmission will be far from idiot proof.

You will need to modulate the throttle manually to achieve smooth shifts, and to avoid burning out the clutches and brakes
If you are going 80 miles per hour and decide to select first gear, it will. And it will rocket your engine right to destruction. (this was a common problem with some allison truck transmission back in the day, where the governor failed and send the engine back to first gear.)
Often the solenoids only control the forward gears. To use park, neutral or reverse will require manual linkage.

I've got a 4 speed gear shifter from a sega rally machine in the shed. I had plans to install it in my 80 w/a442. Although getting the ambition to actually do it is hard, as i'm not that fussed on having a second gear stick, or manual control at all. It might be good for a project later on though.

 

[scottryana]

A750F behind a 2UZ has it's own TCU, but does use inputs from the ECU. I looked at using an A750F behind a 2004 2UZ when I put the supercharged V8 in my FJ55 and it was even going to be a pain in the ass. Not to mention it doesn't use the same transfercase as the 80. So even with a 2UZ conversion I think most people are still using the A343F, which will run with the 2UZ ECU.

 

[FJ55luvr]

I read a swap Jowett did with the tcase out of an 80 or 100 into his new tundra. Very impressive work.

Buck

Indeed, I checked it out. Lucky he didn't have to fabricate a lot of his own parts. His was a very elegant solution.

 

[alia176]

If anyone has a block diagram or a logic explanation of how the A750F operates, that may shed some light on this topic. This should be in the FSM or the EWD, not sure though.

For example: it needs the TPS signal to do this and it needs the Accel pedal (APPS) to do that and so on. We may come to realize that certain signals may be faked or duplicated using relays or by some other means. In our case, the TPS is directly linked to our gas pedal. So, could we use the TPS for the APPS signal as well? Just thinking out loud.

 

[FJ55luvr]

The ideas on the ecomodder link will work, however without creating your own ecu, the basic setup of controlling the solenoids in the transmission will be far from idiot proof.

You will need to modulate the throttle manually to achieve smooth shifts, and to avoid burning out the clutches and brakes
If you are going 80 miles per hour and decide to select first gear, it will. And it will rocket your engine right to destruction. (this was a common problem with some allison truck transmission back in the day, where the governor failed and send the engine back to first gear.)
Often the solenoids only control the forward gears. To use park, neutral or reverse will require manual linkage.

I've got a 4 speed gear shifter from a sega rally machine in the shed. I had plans to install it in my 80 w/a442. Although getting the ambition to actually do it is hard, as i'm not that fussed on having a second gear stick, or manual control at all. It might be good for a project later on though.

I was once driving down the Sierra's and accidentally shifted to reverse going 50mph. I was surprised that it let me. I don't know exactly what effect it had, but the engine stalled . I don't think it damaged anything because everything works fine. I just started it back up while driving and kept going, albeit with shaky hands and an unhappy wife. Lucky I wasn't going around a corner and suddenly lost power steering. So I hear what you're saying.

Crazy question: could you put solenoids to control park, neutral, and reverse?

I'm not sure what it entails to make an ECU, any idea how one would do that?

 

[FJ55luvr]

If anyone has a block diagram or a logic explanation of how the A750F operates, that may shed some light on this topic. This should be in the FSM or the EWD, not sure though.

For example: it needs the TPS signal to do this and it needs the Accel pedal (APPS) to do that and so on. We may come to realize that certain signals may be faked or duplicated using relays or by some other means. In our case, the TPS is directly linked to our gas pedal. So, could we use the TPS for the APPS signal as well? Just thinking out loud.

The attached looks like it's out of the FSM.

 

[alia176]

Ok, I had a chance to look at the above PDF and HOLY COW, the ECU is doing a lot of things that affect the transmission's operation and performance. For starters, take a look at page 162 & 163. The ECU is requiring extra inputs that we don't currently have: input shaft speed sensor, output shaft speed sensor, IGN coil from each cylinder (may be faked), fluid sensor temp #1 & #2 (inside oil pan).

Another interesting to note is that the 750F is about the same weight and has the same # of planetary gears as the 343F (page 152, 1st paragraph). However, the 750F has a more efficient and lighter torque converter and oil pump. Additionally, the ECU doing a boat load of controlling of the solenoids for line pressure and hot fluid management.

Can the tranny be operated w/o doing all of these cool stuff, probably, but I'm no expert. How crazy would it be to simply grab the 750F tranny and the engine ECU along with the harness between the two from a donor Hundy. Then, feed the Hundy ECU the signals it wants from the 80 ECU and hope like heck that you can get the 750F to operate like it was inside a Hundy. That would be a whole lot of work.

 

[FJ55luvr]

Ok, I had a chance to look at the above PDF and HOLY COW, the ECU is doing a lot of things that affect the transmission's operation and performance. For starters, take a look at page 162 & 163. The ECU is requiring extra inputs that we don't currently have: input shaft speed sensor, output shaft speed sensor, IGN coil from each cylinder (may be faked), fluid sensor temp #1 & #2 (inside oil pan).

Another interesting to note is that the 750F is about the same weight and has the same # of planetary gears as the 343F (page 152, 1st paragraph). However, the 750F has a more efficient and lighter torque converter and oil pump. Additionally, the ECU doing a boat load of controlling of the solenoids for line pressure and hot fluid management.

Can the tranny be operated w/o doing all of these cool stuff, probably, but I'm no expert. How crazy would it be to simply grab the 750F tranny and the engine ECU along with the harness between the two from a donor Hundy. Then, feed the Hundy ECU the signals it wants from the 80 ECU and hope like heck that you can get the 750F to operate like it was inside a Hundy. That would be a whole lot of work.

Cool thing is that you can source the transmission from a number of sources so would be much easier to find. According to Wikipedia:

2003+ 4Runner (4x4)
2005+ Tacoma (V6 4x4)
2009 FJ Cruiser (Canada V6 4x4)
2003-2009 GX 470 (4x4)
2003-2007 LX 470 (4x4)
My addition (should update Wikipedia article): 2003-2007 Land Cruiser.

It might be interesting to still try the manumatic and if it doesn't work, get all the rest of the stuff and faking signals.

My overall goal is to get my 80 as best fuel economy as I can so I will be more apt to drive it and feel slightly less guilt when I do. And it doesn't seem to cost anything for the 80 to get this transmission and its probably better in every way.

 

[rove_mcanus]

Crazy question: could you put solenoids to control park, neutral, and reverse?

I'm not sure what it entails to make an ECU, any idea how one would do that?

You could use a stepper motor to move the shift lever through it's ranges. Similar to how the cruise control motor opens and closes the throttle.

Making an ecu is probably a cinch if you have studied computer science/electronic engineering
To make a basic ecu that automates shifting based on a few basic inputs (throttle position, vehicle speed) would be significantly easier then trying to recreate the standard 100 series ecu with its 'ai' shifting.
Although I am no electronics engineer, i do have a basic understanding of some principals. There will be the phyiscal side of the electronic system such as assembling the circuit board and wiring it all up, and then there will be the programming of the microprocessor to take in all the inputs, process them and then output the signals to the transmission. The programming side will have the steeper learning curve.

There is also the concern of the shifter. Although you could use a rotary multi position switch, that would be a bit crappy to operate whilst driving. Using a sega shifter like I have would not work either as it only has 4 positions, and you need at least 5.

That leaves the option of building your own shifter. The sega one is fit for purpose and you could expand on it's design to make a 6 position shifter. Obviously that will require a reasonalbe level of fabrication skills.

 

[alia176]

Cool thing is that you can source the transmission from a number of sources so would be much easier to find. According to Wikipedia:

2003+ 4Runner (4x4)
2005+ Tacoma (V6 4x4)
2009 FJ Cruiser (Canada V6 4x4)
2003-2009 GX 470 (4x4)
2003-2007 LX 470 (4x4)
My addition (should update Wikipedia article): 2003-2007 Land Cruiser.

It might be interesting to still try the manumatic and if it doesn't work, get all the rest of the stuff and faking signals.

My overall goal is to get my 80 as best fuel economy as I can so I will be more apt to drive it and feel slightly less guilt when I do. And it doesn't seem to cost anything for the 80 to get this transmission and its probably better in every way.

Keep in mind that all the Hundy ECU craizness is to provide smoother shifts (lower line pressure) while keeping up the MPG. Would the 750F really need all that control just to operate? I don't know.

I sent an inquiry to Rodney in Aus to see if he has done any of this conversion. I'll post up the response. I too, would like the 5 speed tranny for a better driveablity while keeping the 1fz. However, the cost would have to be very low; otherwise, the I6 GM Atlas with either a 4l60/80E tranny may have to go in. This is way far in the future but it doesn't hurt to plan and see what shakes out.

 

[FJ55luvr]

Keep in mind that all the Hundy ECU craizness is to provide smoother shifts (lower line pressure) while keeping up the MPG. Would the 750F really need all that control just to operate? I don't know.

I sent an inquiry to Rodney in Aus to see if he has done any of this conversion. I'll post up the response. I too, would like the 5 speed tranny for a better driveablity while keeping the 1fz. However, the cost would have to be very low; otherwise, the I6 GM Atlas with either a 4l60/80E tranny may have to go in. This is way far in the future but it doesn't hurt to plan and see what shakes out.

That would great if someone's already done it! My priorities are to maximize stock Land Cruiser, then LCs from other years (preferably later years), then maximize Toyota components.