Petrol vs. Diesel Transmission Differences

[alaskacruiser]

I've been trying to get a straight answer on the differences in the auto transmission (A442F) between the 1FZ petrol and 1HDFT diesel motors in the 80 series. From what I can find, it seems like it's the torque converter and valve body that are different, as well as the ECU. The transmission is otherwise the same. Is that correct?

 

[TheBussman]

I've been trying to get a straight answer on the differences in the auto transmission (A442F) between the 1FZ petrol and 1HDFT diesel motors in the 80 series. From what I can find, it seems like it's the torque converter and valve body that are different, as well as the ECU. The transmission is otherwise the same. Is that correct?

mostly, 93-94 1fz a442f does not have the 2nd gear start mode like the factory 1hdft 95+ trucks had. 95+ 1fz trucks had a a343f. if were talking about 93-94 only gas vs diesel the valve body I'm pretty sure is the same even although I did swap mine out anyway because I wanted a wholesale one. the torque converter is for sure different but it does seem like it would bolt up and work you would just have a much higher stall speed. bell housing is obviously different. ECU is different but I'm told that a 1FZ auto trans module will run the trans even without all the inputs from the gas ECU, I'll know for sure soon. diesel throttle cable is a little longer. I pulled up both gas and diesel trucks of the same year on parts diagram and went back and forth looks the same to me.

 

[Malleus]

 

[alaskacruiser]

After some reading, the differences between the 1fz and 1HDFT A442F include:

- 2 1st gear clutches in 1HDFT version vs 1 in 1fz version
- different valve bodies
- different torque converters

 

[Squash]

Year of manufacture matters.
Early 90/92 diesels have the fully hydraulic A442f
92 on the A442f electronic version.
Yes! BOTH are the same number.
If you want to rebuild try the "Transtar kits".
These guys should be also capable of rebuilding your torque converter.