Re: Overdrive not kicking in
The A4LD tranny's like that found in your Ranger are notorious for losing overdrive. The OD drum fails catastrophically, causing you to lose OD WITHOUT losing any other gear. Reason being is that the A4LD is just a C-3 with an OD added to the 3 forward gears. Driving it around in that condition isn't a very good idea. Pull the dipstick on the tranny and take a close look at the fluid. There will most likely be a bunch of shiny metal flakes in it, or it will be a burnt brown color. You can either drive it until you lose all forward gears or rebuild it now. There's pretty much no way around it.
Being an '88, consider yourself lucky it lasted that long. Despite proper maintenance, I rebuilt the A4LD in my old Ranger after only 80,000 original miles.
1992 Ford Bronco
E4OD- B&M Stage 2 shift kit
Full 3" stainless Bassani Exhaust
32" BFG's/stock suspension
"No replacement for displacement."
"Our lugnuts require more torque than most Honda's produce!"