2.0tdi + a4ld, shifting rpms and 4th gear?

[Lientz]

Looking into swapping a 2.0 tdi into my 2.9l 89 xlt and i want to keep the automatic a4ld (after rebuilding it). I know the 1-2 and 2-3 are not computer controlled, but how exactly does the 3-4 shift work? Is it a x-time@y-speed then the computer tells it to engage OD or how does it work? Also is there anything special, beyond a lower stall torque converter, that i will have to do to make it shift at the lower RPMs of the diesel motor?

Thanks in advance!

 

[franklin2]

Here is a article that explains this transmission. If you read on down in the article, it explains the older a4ld had a wire connection for the lock-up convertor, the rest of the trans was automatically shifted. They say starting around 1993, the trans was changed to where you had two wires, one for the lock-up and the other for the 3-4 shift. So the 3-4 shift on the later trans was electronically controlled.

Ford Ranger A4LD Automatic Transmission