i have 97 4x4 with the 5.4 and it shifts great, but when i get done doing some highway driving for a while it starts shifting hard but thats the only time it does that, around town its fine, but on the interstate or highway it will start shifting hard after a certain distance, dont know what the problem is, if you have any info that would be great

 

my truck did the exact same thing. it would shift fine in town and once i got on the highway then off the highway it would shift pretty dang hard until i turned my truck off then on... anyway i did some research and found a ford technical service bulletin... it says to replace the speedometer gear in the extension housing of the transfer case... its very easy to do so i went to the dealership and got the new speedometer gears... the one for the output shaft and the one on the speed sensor then i performed the bulletin and it fixed my truck. heres the bulletin:

LIGHT TRUCK:
1997-1998 EXPEDITION, F-150, F-250 LD
1998 NAVIGATOR This TSB article is being republished in its entirety to correct the parts listed.
ISSUE:

The Malfunction Indicator Lamp (MIL) may illuminate and Diagnostic Trouble Code (DTC) P0503 may be stored in memory. There may also be transmission shift concerns and/or erratic speedometer operation. This may be caused by the speedometer drive gear being loose on the transfer case output shaft.
ACTION:

Replace the speedometer drive gear. The new gear has a tighter fit and should reduce the possibility of erratic signals. Refer to the following Service Procedure for details.
SERVICE PROCEDURE

1. Perform normal diagnostics as outlined in the 1997 or 1998 Powertrain Control/Emissions Diagnosis (PC/ED) On-Board Diagnostics II (OBDII) Service Manual. Service as required.
2. If no concerns were found or the concern is still present, replace the speedometer drive gear.
3. Remove the four (4) rear driveshaft flange bolts and remove the rear driveshaft. NOTE:TO MAINTAIN INITIAL DRIVESHAFT BALANCE, MARK THE REAR DRIVESHAFT YOKE AND AXLE FLANGE SO THEY CAN BE REASSEMBLED IN THEIR ORIGINAL POSITIONS.
   
4. Remove the six (6) extension housing bolts and remove the rear extension housing.
5. Remove the speedometer gear spacer then push the speedometer drive gear toward the transfer case and remove the steel ball. The speedometer drive gear can now be removed from the output shaft.
6. To install the revised Speedometer Drive Gear (F7TZ-17285-AA), reverse the removal procedure. NOTE:THE NEW SPEEDOMETER DRIVE GEAR WILL HAVE A SLIGHT INTERFERENCE FIT, HOWEVER IT WILL GO ON TO THE OUTPUT SHAFT BY HAND. DO NOT HEAT THE GEAR.
   
7. Before installing the extension housing, apply a small bead of sealant to the transfer case cover and extension housing mating surfaces. Use Ford Ultra Silicone Sealant (F7TZ-19554-AA or equivalent).
8. Top off transfer case with MERCON® (XT-2-QDX).

PART NUMBER PART NAME F7TZ-19554-AA Ultra Silicone Sealant F7TZ-17285-AA Speedometer Drive Gear XT-2-QDX MERCON®

 

how is the color of the tranny fluid?

 

the tranny fluid looks great, im pretty sure its the speed gear sensor

 

okay so there is two things i need to change? because ive heard there is a sensor on the differential and a sensor on the transfer case

 

not the sensors. the speedometer gears inside the extension housing of the transfercase very very easy to replace read what i posted before. it gives you all the instructions

 

alright so i dont need to mess with anything in the differential?

 

most likely not. im thinkin you should scan for codes and see if you have any codes before you go takin stuff apart.

 

how much did that part cost and where did you get it from?

 

I had a 99 4x4 once and it did the same thing I put some Lucas transmission fix in it and it never did it again