I have a 2000 Ford Ranger, 2.5 liter, A4LD auto trans, 150,000 miles. I have changed fluid, filter, shift solenoides. When I'm driving in "D" the speed ohmeter drops off, then the trans seems to go into neutral. Couple of seconds later it is fine. No problem with shifting between gears. If I put it in 2nd, there is no problem at all. I have no CEL codes. There is no speed sensor on this trans. I have also went to the boneyard and purchased another trans. Changed fluid and filter.
installed, same issue. I believe it is electrical in nature.
I have been doing some research since I posted this thread. The 2000 Ranger has a speed sensor on the rear axle. My ABS light is on. I am going to locate and pull the sensor, replace and check back. I also found out that the 2000 does not have a vacuum modulator. It id electrical. If anyone else knows anything, I would love some input. Thanks