97 E4OD odd shifting

[Russ]

Helping a Buddy out with his 97 F250 E4OD. When cold everything works fine. After about 40 miles, stays in 1 gear until throttle is lifted, or manually shifted into 2nd gear. Goes into 2nd, then when shifted into drive, goes into drive then right into OD. Shifter light is working and not blinking. New VSS installed in rearend. Goes back to normal shifting if left sit for a 1/2 hr or so. Then pattern repeats after about 30-40 miles. This is a new to him truck. Any thoughts? Thanks.

 

[OLDBULL8]

Sound's like it might be overfilled, OK when cold, NG when hot. Check fluid level when hot. Overfilling causes aireation,which causes low pump pressure when hot, pump pumping air and fluid. Also check proper shifter position at the tranny. It probably will go into OD quickly when shifted into drive above 35-40 MPH at a level speed, that is a function of the Electron control.

What is the condition of the fluid, brownish or smells burnt, if so drain and replace fluid.
Refer to 7.3 tech articles for flushing if needed.
Other causes:
Low pump pressure.
Solenoid S2
Dirty or sticky valves

 

[geonc]

I'm not the sharpest on auto's but from past experience....any brake lights out?

While driving in OD, with your right foot holding a steady road speed...gently depress the brake pedal and release---can you see the tach change rpm/feel the conv un-lock?

 

[OLDBULL8]

"New VSS installed in rearend."

Missed that statement, According to AZone component location, the VSS is located on the transmission.

 

[trackspeeder]

"New VSS installed in rearend."

Missed that statement, According to AZone component location, the VSS is located on the transmission.

They tossed the VSS in the rear on this truck.

 

[trackspeeder]

I'm not the sharpest on auto's but from past experience....any brake lights out?

While driving in OD, with your right foot holding a steady road speed...gently depress the brake pedal and release---can you see the tach change rpm/feel the conv un-lock?

Try this. Brake lights will do funky things to the tranny.

 

[Russ]

Don;t think it is a bulb, It seams more heat related. Fine when cold, but bad when warm. Had a scanner put on it and IIRC when it faulted, it said no signal from VSS. Gonna do a fluid and filter change this weekend. Thanks for the replies. I'll pass on the suggestions.

 

[Russ]

Went for a ride in it last night. whenever it is acting up. and the OD button is pushed the rpms jump but no gear change is noticed. Not sure if it is in OD or still in drive.

 

[geonc]

Went for a ride in it last night. whenever it is acting up. and the OD button is pushed the rpms jump but no gear change is noticed. Not sure if it is in OD or still in drive.

It doesn't "change gears" Gary....it is the TC locking/unlocking.....

If you really want a good example of just how critical brake lights/ turn signals are......drive down the road at a constant speed above 45 mph and turn on the 4 way flashers and watch the tach ...the TC cycles with the flash pulse.....

Does the truck have cruise...and does it work?

 

[Russ]

OK brake lights check ok. If time allows gonna change filter this weekend.

 

[trackspeeder]

OK brake lights check ok. If time allows gonna change filter this weekend.

That was going to be my next suggestion. Check for anything nasty in the pan. Metal ect.