No overdrive 4r55e

[mackmanj]

First I would like to say hi to everybody and that I am new to this forum. My son has a 95 ford explorer with the 4.0 & 4r55e trans. Coming home from work one day the OD light started flashing and overdrive stopped working. We got codes 646 and 647, I pulled fluid from the transmission and it looked normal with no burned smell. We bought this rig being told that the trans had been rebuilt about 6mo before we bought it. It can be driven all you want with the OD turned off, as soon as you turn it on it flashes OD light and has to be reset.It shifts fine through all the gears except OD which it doesnt shift into at all. I am going to start working on it this weekend and any help on where to look will be appreciated. Thanks, Jay

 

[PopRichie77]

As you may know the codes indicate 2nd gear and 3rd gear failure. Do you have engine braking in manual first? Will it move in manual second? Turning OD off is a function of the PCM. Check the plug for clean contacts and good connection at the trans on driver side.

 

[mackmanj]

Engine braking in first? Yes. Move in manual 2? Yes.

 

[PopRichie77]

If you have a pressure gauge take a reading in drive , OD off and with OD on. The solenoid wiring in the trans may be bad, insulation comes off the wires.
The OD band may be broken or the OD servo may be bad. You can check the band when you have the pan off. One way is to adjust it and if it won't take 10 ft/lbs it is broken.

 

[mackmanj]

Thank you for the help Poprichie77. I will def look at the wiring while I'm in there. Thanks, Jay

 

[mackmanj]

Finally got the chance to work on the old girl. I found that the fluid was good, and there were no extras in the pan. The internal wiring harness has a bunch of the insulation gone so I ordered one off of ebay. I pulled the servos and found that the OD servo rubber has a torn place on it. It looks like the edge was rolled when it was installed on the rebuild. I had to order the servo and it wont be here till Tuesday. Hopefully this all that is wrong with the transmission. My harness that came out of the tranny had white, green, red, and gray colors. The trans temp sensor was also an individual unit on the harness. The harness I got off ebay has light brown and brown wire colors only and the trans temp sensor is part of one of the solenoid connectors. Will this harness work in my transmission. Thanks, Jay

 

[reddangerranger]

hey im sorry for stealing from this thread. Ok so this is kind of embarrassing but, i need a wiring diagram or a picture of a VB harness out of a 4r55e tranny.. i was pulling out the VB and pulled like 5 wires off their connectors!! any help would be great!!! thank you!