A4LD was Fords first light duty OD transmission and it used a solenoid(TCC solenoid) for earlier torque converter lock up for better MPG, the engine computer controlled this and all future solenoids
Any torque converter will lockup for direct drive when speeds gets high enough, but that doesn't happen driving around town, which is one reason automatics had much lower MPG than Manual trans
The TCC solenoid/computer has the benefit of driver input, i.e. gas pedal and brakes, so computer could lock torque converter earlier, and unlock it when stopping
A4LD got a 2nd solenoid(3-4 shift) in 1987/88 for better shifting to OD, so it didn't "hunt", i.e. shifting between 3rd and 4th all the time
Most transmission shops had NEVER SEEN any OverDrive transmissions before, let alone automatics with solenoids
But that didn't stop them from "fixing them" and of course 3-6 months later the A4LD is back at the shop because they goofed, but they wouldn't say "I goofed" what they say is "it was a bad design by Ford", because that is what many people do, lol, "Hey, not my fault man"
And thats where the "A4LD is a bad trans" comes from, if properly repaired or rebuilt it lasts as long as any automatic
And as said the A4LD, 4R and 5R are the same transmission except for some updated parts which you can use in the A4LD
A4LD came out in 1985 and 5R was last used in 2011, thats 26 years for same automatic, and no matter what you might think of Ford, lol, even they wouldn't stay with a bad design for 26 years
A4LD and the 4R and 5R were only for use with 4cyl or V6 engines, not V8s
A4LD was used in these vehicles:
1985–1990 Ford Bronco II
1987–1993 Ford Mustang (when equipped with the 2.3 I4)
1987–1988 Ford Thunderbird (when equipped with the 2.3 I4)
1985–1994 Ford Ranger
1986–1994 Ford Aerostar
1991–1994 Ford Explorer
1991–1994 Mazda Navajo
AOD was a larger transmission and made for V8 power/torque, and had no solenoids so no computer needed
AOD-E got added solenoids and needed a computer
As said the 4R70W was after the AOD-E and it had full solenoid shifting like the 4R44E, but for V8 power