2002 f150 5.4 4r70w swapped trans with junkyard trans and when i plug in the oss sensor [only sensor it has] the speedometer will jump to 80 mph in about 30 ft also shifts thru gears super fast in od in 30 ft,unplug and does better but no speedometer,,,the junkyard trans has a place for a tailshaft vss but only a plastic plug in place and my truck has no wires for one anyway,,,,i think the trans we put in is a 03-04,,,any help appreciated.

 

Anyone have any info on this?

 

Are you sure it is a 4R70w transmission and not a 4r75w or 4r100 you put in?
If you had to change the flywheel from the one you had to get the other to bolt up is the only way the 4r100 or E40D would go in as their flywheel is different.
They will not shift correctly in a system set up for the other and all will bolt-up to a 5.4 or a 4.6.
Hate to say it, but you may have to flash the PCM for that transmission to work right.
You need to read the transmission S/N type to make sure what trans you have and what trans you took out of yours.

 

it shows to be a 4r70 in now.

 

Have you changed the OSS sensor?
If you still have your old transmission, take the one out of it and place it in the new trans. Sounds like that may be your problem if the trans are what you said.
That little sensor controls the shift input as well to the PCM on the reading of the speed of the shaft.
If you have a scanner that can read transmission codes, there should be a code of PO721

From Ford:
Possible Symptoms:
Engine Light ON (or Service Engine Soon Warning Light)
Speedometer improper reading
Possible shifting problems

P0721 2002 FORD F150 Description The Output Shaft Speed (OSS) Sensor provides the Powertrain Control Module (PCM) with information about the rotational speed of an output shaft. The PCM uses the information to control and diagnose powertrain behavior. In some applications, the sensor is also used as the source of vehicle speed. The sensor may be physically located in different places on the vehicle, depending upon the specific application. The design of each speed sensor is unique and depends on which powertrain control feature uses the information that is generated. The Diagnostic Trouble Code (DTC) will set if the PCM detects an OSS sensor out of range circuit.
It is just plugged in and held by a bolt. Take the one bolt out and unplug the harness first, twist the plug a little to get it to break loose, and work it out.

 

Brand new oem on way,i hope thats it,,,my old trans was hauled off so im in the dark sorta speak,,,,thank you very much for that info.

 

Your more than welcome and I hope this will fix your transmission.