Hello everybody I have a 1996 Ford F-250 460 e4od and here is my problem
I'm having typical e4od problem hard shift I have replaced the VSS 5 time now 3 through Advance Auto and 2 through the dealership each one helped for a week and then back to hard shifting . I put a new pigtail on the VSS still no help I check fuse 8 and 18 were perfect and now just the other day the odometer and speedo is not working the tack and all the other gauges are reading just fine I pulled number 8 fuse waited 5 min and put it back in and it works fine until the truck gets up to operating temp and here comes the hard shifting. I am at my wits end all I want to do is drive my truck I'm tired of driving my wife's Windstar so if there is anybody out there please help me thanks in advance -- Classic

 

Did you take a peek inside the rear diff and eyeball the tone ring? This is a metal ring that works with the VSS.

How did you check the fuses? Visual check ain't always good enough... probe them in-circuit with a test light.

And finally, pull the PSOM (Programmable Speedometer/Odometer Module, on the back of the instrument cluster behind the speedo) and eyeball it's PC board. The board uses electrolytic capacitors which with age and heat will eventually blow and leak electrolyte all over the board... you can probably guess what happens then.

If you don't see any obvious damage to the PSOM then it's time to start checking power and signal circuits.

 

dixie 460 is there any spesific i should be looking when i take off the diff cover or the psom also should i do both or just the diff?? as u can tell im lost on this truck i fix 6.0 for a living and drive a ford v10

What would cause the odometer and the speedo to just go out like that and come back

 

If the odometer display goes blank then you have a power problem or the PSOM has a thermal intermittent.

 

https://www.ford-trucks.com/forums/1...s-but-why.html

 

update i just drove the truck a hour ago after changing the diff fluid and vss again making sure even with a feeler gauge that is was 0.015. the truck ran beautiful after hour i notice hard shifting again the speedo climed so nice and straight no bouncing what the hell is going on the the overdrive light started falshing and back into first gear again whats going ON please help

 

Looks like a PSOM going bad, I had the exact issue with my E350. The capacitor leaked and damaged the PSOM pcb. The speedo and odo worked fine, but the PSOM was not sending good speed info to the engine ECU and speed control(my quit working while PSOM malfunctioned too).

The best place to get a PSOM is a junkyard, but look them over before buying. They are getting some years on them and this is now a common problem!

Any PSOM from the 92 to 96 E and F series will work. You just have to reprogram the correct ratio factor in and mileage will not be the same unless the EEPROM is copied to new one.