I have a 1998 Ranger 4WD 4.0L 5 spd. automatic (5R55E) 110,000 miles --the transmission has started not downshifting properly -- noticed it when starting to go uphill in mountains -- intermittently (at least 75% of the time) if below 2400 RPM and under load it does not downshift -- it attempts to downshift and there is sort of a clunk/lurch/hesitation but does not complete the downshift -- can be downshifted manually or by briefly letting up on the accelerator and then depressing it -- will also downshift under load by taking it out of overdrive (if OD is already off it behaves the same way as with OD on) -- fluid appears a normal color to me and the OD light has never flashed -- have taken it to a Ford dealer and they cannot find the problem -- does not show up with their computer diagnostics -- I believe the function not working is called "Torque demand downshift" -- appears to me the PCM must command a gear change and a torque converter command (and probably more) -- notice there is a "4-3 downshift valve" that is controlled by one of the solenoids -- wonder if this guy could be the culprit??? -- wondering if a flush job might fix this ???-- would it be a good idea to add one of the "cure-all" solutions prior to changing the fluid -- if so what is the best one to use ??

 

Have you fixed your problem with the downshifting yet? I have a 2000 Expedition AWD 4x4 4.6L and have had issues with downshifting from OD to D for the last few months. This last week it has really gotten bad. I have checked everything I can think of and Ford of course can't duplicate the problem because there are not any hills or inclines close. It is steadily getting worse. Any suggestions are welcomed! If I figure something out this weekend I will get back online monday Thanks.

Jeromy
2000 Ford Expedition AWD 4x4 4.6L

 

Since posting that original question I have driven an additional 23,000 miles including a trip from Florida to Alaska and back -- the problem has become a little worse during that time -- talked to a Ford mechanic that seemed to really understand this transmission (Paradise Ford, Cocoa Fl -- don't remember his name) -- he thought my analysis of the 4-3 downshift solenoid was a good possibility but said it could also be the computer or something else -- in that replacing that solenoid and valve is fairly expensive I have just continued to drive it -- trying to decide whether to make another trip up the Alaska highway with this transmission -- sorry I couldn't be of more help -- Gary

 

I have also noticed something else. I have a module mounted under the steering wheel that was put on for trailer brakes. When I hit my brakes now the light starts flashing like there is a short or something. IT NEVER FLASHED BEFORE. And its not really a "flash" it really looks like a short of some kind. Does anyone know what the black square box is that is located in the dash on the passengers side? Its under that piece of dash that just pops out. Its about 6x6" and it was making a rattleing noise and I put some cardboard in there and made it quit rattleing. I can't remember if this was done about the same time as the downshifting or not?. Any help would is appreciated. Thanks