I just recently purchased a 1999 Ford Ranger with a 3.0 and an automatic transmission. The previous owner said that he just had rebuilt the engine which runs great but he found that the transmission would not shift into any gears. He purchased a used transmission from a salvage yard but it had the same symptoms. I wanted to know if there were any controls I could check before pulling the transmission to replace it. I know these have a lot of electronics and I'm concerned there might be something externally causing it not to shift in gear.

 

Welcome to the forum

Well there is one hard learned lesson on installing an engine to an automatic transmission, or installing an automatic to an engine

You MUST seat the torque converter into the transmission FIRST then you can bolt the engine and trans together

Many do not do this, and the result is a broken Front Pump(main pump) so transmission can not work, no pressure from pump, so no gears at all

Short video on seating torque converter: www.youtube.com/watch?v=g7klzEV0kng

Applies to ALL automatics

If you do not line up the torque converter with the input shaft and pump and tighten bell housing bolts you will break pump tabs off inside, bye-bye transmission

Did this once on my first automatic, lesson learned


The Electronics on automatics is for smoother and correct RPM shifting, better MPG and driving, trans will work without any wiring plugged in, it will just shift hard and RPMs will go higher before shifting.
No gears means no internal pressure, all automatics run on pressure
Reverse requires highest pressure, which is why slow or no Reverse is when you know trans is losing pressure internally, seals or gaskets are leaking inside