96 F350 wont shift into or out of overdrive

[7.3IH_Eggrole]

So my Dad's 1996 F350 PSD 4x4 has been having some shifting issues lately. It is an automatic and a month ago he had the transmission rebuilt. Now most of the time it will not go into overdrive, it doesn't matter if its first thing in the morning or after its been run all day. This has been going on for at least a week straight. Then today on the way home the truck decided to go into overdrive and would not come out.

Other things that have been done since the transmission rebuild are:
New cam shaft position sensor
New injectors (the transmission shop said it wasn't turning up enough to get into overdrive, and 2 of them were bad in the end anyway)

Any ideas on what can cause this, the transmission shifts fine in the rest of the gears, just doesn't go into, and now come out of, overdrive. I know I'm not giving yall very much to work with here, but I'm at a loss.

 

[OLDBULL8]

New injectors (the transmission shop said it wasn't turning up enough to get into overdrive, and 2 of them were bad in the end anyway)

That guy is full of dodo about that. The PCM controls the shift points by inputs from sensors. The slowest speed it will shift into OD is 36 MPH, RPM's have nothing to do with it per se. Pretty sure you can go faster than that.
Try turning OFF the OD if it won't shift down to 3rd. Your wires in the steering column to the OD switch might be pinched or bare shorting out. Take the column cover off (4 screws) you can plainly see the three small wires. The OD solenoid may be bad. that's inside the tranny in the solenoid pack, checkout the connector on the passengers side for corrosion, doNOT pry out with a screwdriver, just wiggle it out. There should be a sheet metal shield there to keep the exhaust pipe heat from damaging the wires and connector.b Only other thing I can think of is, if the rebuilder didn't update the snap ring on the OD clutch pack to the circular one, it could have jumped out, was/is a common problem. Called retaining ring 78421 in pic.

You must be registered for see images

 

[rthomas]

Servo pack, Id bet he got a bad one during the rebuild.

 

[OLDBULL8]

Here it is 5-6 days after the question, 2 answers and no reply. God I hate that.