My 95 Ranger has a problem that 1 mechanic and 1 transmission specialist has not been able to figure it out. The Ranger is a '95, with 4L V6, and 4WD with automatic transmission. Under certain driving conditions, the transmission seems to go into neutral for no reason, the engine revs up like it has no load and then it goes into gear again. I can make it happen every time by driving up to about 30mph, coasting to about 20mph and then accelerate. The rpm will jump up a bit, the truck decelerates a little then engages into gear again and off we go. This can also happen sometimes if traveling around that speed and going up a slight incline, and perhaps accelerating a little. The most exciting time it does it is at random times when traveling between about 40mph and 55mph. It seems to happen only when cruising on the highway at a steady speed, not during acceleration. Turning off the overdrive does not stop it from happening, but it has never happened while driving in gear position "2" at any time at any speed. I cannot make it happen at will as at the lower speed. When the outside temp is below around
30 degrees F, the problem is practically nonexistant as far as the higher speed phenomenon is concerned. I still does the lower speed thing at any temp though. The transmission was rebuilt at around 90K, the problem existed both before and after it was rebuilt. It did run better after rebuild, but this problem never went away. The rebuilder did not have any idea what it was that was happening. The fluid is not low, never was, and it is not burnt as far as my nose can tell.Thanks for any ideas..............T