I have a 2001 F350 with 7.3 Diesel and 4R100 Auto Transmission,it has started to act weird.

Seems like it is shifting in and out of overdrive or maybe the converter is locking and unlocking, when you cruise down the road at a steady speed while in 4th gear the truck suddenly seems like it's downshifting, the RPMs wil suddenly shoot up and then return to normal. This happens randomly either on the highway on cruising inner city 45-55 mph.

Transmission temp seems okay, I have a gauge.

Truck does have a diablo sport programmer. Every since I got the truck, it came with the programmer, and shifts smooth with it. If you take the programmer out and turn it back to Stock Tune, the truck shifts hard.

I already had the cooler valve changed, and also the shift solenoid pack, but Truck is STILL doing the same thing.

This just started happening last week.

I'm hoping somebody can give me an idea on what to change next?

Am I causing damage by continuing to use the truck how it's acting?

Should I keep it parked until fixed?

 

what is happening is your torque converter and or your lock up solenoid is on its way out. if the truck continues to be driven trans will overheat and fry the clutches and will usually blow the front pump seal.

 

Correct sad to say but it's probably time for a rebuild mine was doing the same thing took it to ford duh big mistake. Ended up taking it to a reputable trany rebuilding place and had them rebuild it correctly and upgraded parts to handle the Banks tuner i had installed. Money well spent.

 

I seem to be having a similar issue. I have a 2001 7.3 with the 4r100 and the issue is when I am on a 70+ road with od on she won't go past 2600 rpms but with the od off it hits all the shifts just right. Would anyone be able to help?