1995 F-150 XLT extended cab 4X4 5.0 / 4R70W with trailer towing package

Recently installed a reman transmission at 185K to alleviate some concerns about towing reliability.

After clearing codes now, I can drive it about a week with no issues, it will run and shift like a new truck. After what I am guessing is the prerequisite start stop cycles where the computer learns and then transitions from learning to normal run status, I have an issue.

It starts with the transmission not wanting the shift down completely at speed and the torque converter not locking up. RPM's are 500 to 750 revolutions higher at the same MPH than when its running correctly. The overdrive light then starts flashing constantly.

When this first started happening I could just disconnect the battery and it would run fine for another week or so. That no longer works. Clearing stored codes then worked for a week or so but now after clearing them, and its running and shifting like a new truck, even 2 to 3 miles later it goes into limp home mode and the overdrive light then starts flashing constantly . . . . again !

The speed sensors on the tranny and rear end are new. I can only think the wiring harness integrity to be suspect now but time hasn't allowed me to change it out yet.

I am concerned with a 628 code I'm getting because the vernacular on it says " lock up solenoid " but for cars only. It makes me wonder if possibly I have had a car transmission, with a 4X4 tail-shaft, pawned off on me by the reman operation it came from?? If that is even possible?

What say you FTE brain trust ?

 

628 is excess torque converter slippage. By any chance did you opt for a high stall converter?

I believe you may have the E4OD. Never was installed in cars, but there were two distinct valve bodies.

 

All nomenclature for replacing the PCM said it was a 4R70W . The replacement transmission came with a torque converter with an 1800 rpm stall compared to the OEM units which are 1600 rpm stall. The transmission source advised it would be unnoticeable to the PCM or in driving characteristics .

My quandary arises in that the performance of the drivetrain is basically flawless while operating on the PCM loop for learning but goes to crap after that sequence where my mileage would increase appreciably.

 

i would think you are losing pump pressure. had a reman in my 96 when i bought it. started acting similar too yours. then shortly afterwords it simply would neutral out when i would stop the truck. had to rev it up before it would jump into gear. i replaced it with a good used one from a reputable salvage. have put 50k on the used one with no problems. i would look at any possible warranty you may have and take it back to where you got it rebuilt.