I have a 1996 f350 crew cab with a 7.5 and a e4od transmission... I'm having problems with the transmission shifting hard after removing from overdrive ... I can reset the problem by disconnecting the battery and it works fine until I turn the overdrive off again ... the check engine light does not come on at all ... any ideas out there ??? I have tried almost everything and getting extremely discouraged

 

it's going into limp mode, you need to pull the codes to see what is causing it.. You can have DTC codes set WITHOUT a check engine light being on. You may not get any codes if you have just unhooked the battery, leave it connected until you get the trouble showing up.

 

I wonder why they didn't have those trucks ECU's flash the OD cancel light like the old IDI stand alone E4OD trans unit,so you've got a notification codes are up.I know you've still got the firm shifts associated with limp mode but still.

 

All PCMs flash the OD OFF light when codes are stored.

 

x2, didn't think they ever changed that. I've talked with several people in the past though who never noticed the light flashing. If you don't know to look for it, it isn't all that great at getting your attention.

OP, as said above, run the truck again until you start getting the hard shifts. Bring it home and don't pull the battery. You'll need to pull your stored codes so we can see what's causing the truck to protect the transmission. The reason you're able to fix the problem temporarily is that you're forcing the truck to re-detect the issue each time you pull the battery. As soon as it does, it puts the transmission in "limp mode" to guard against potential damage.

You'll likely find some type of speed sensor related code. This could be an easy and inexpensive fix once you've done the above.

 

I have taken the truck in when in limp mode ... the tech had determined that it was a grounding issue and also a throttle positioning sensor that the values were not matching up ... after replacing the tps and adding ground straps the problem seemed to be solved until last weekend... could a faulty ignition switch cause any issues with the transmission?

 

Where did they add ground straps?
I would say no on the faulty ignition switch.

 

They added 1 on each side of the housing to the frame and ran a designated cable to the battery itself ... the transmission was rebuilt about 20k miles ago by the previous owner because of the same problem... the ignition switch went out on our last trip also .. I was just wondering if there could be any connection???

 

I would go back and ask them for the specific codes this time.Post them here when you get them for more help.

Oh this isn't a PSD is it.Are getting the codes just as difficult (expensive scanner required) as getting them from the trucks with power strokes?

 

It does not sound like they know much about the truck.
The frame is not a ground point for the truck. The frame is only used as a ground for the trailer ground and not the truck.
Other than push on radio static straps there is no ground path between the cab, engine and the frame.

 

Thank guys ... I get the codes this weekend and see what's up ...thanks for your support