97 trans blinking o/d off and hard shifting

[jamesleber]

I have a 1997 ford f250 with the diesel. I parked it one night, it had been driving fine, but the next morning I started my truck, drove out the driveway and the O/D off light was flashing and shifting VERY hard. Is there a common fix for this? Or does anyone have any idea what might have went wrong? Please help, I need my truck and I am afraid to drive it too much with the hard shifting. It sounds like a loud thunk and revs higher than normal to shift. I have not taken off road nor has it rained. Just stumped on how to go about fixing the problem.


ANY and ALL help is GREATLY appeciated!!


James

 

[oi8228oi]

welcome.... this was disgussed recently and i want to say its related to vaccumee but im not 100% stick around and im sure someone will remember... also try a searh for posts about O/D light

 

[jamesleber]

I have looked for the search link and can not find it. Either I am blind or it is not here. If I am over looking the link, please let me know where it is and I will be glad to use it.

Thank you!!

James

 

[action4478]

Mine was the speed sensor wires on the rear drive axle, Broken inside the wire

 

[powerboatr]

I have a 1997 ford f250 with the diesel. I parked it one night, it had been driving fine, but the next morning I started my truck, drove out the driveway and the O/D off light was flashing and shifting VERY hard. Is there a common fix for this? Or does anyone have any idea what might have went wrong? Please help, I need my truck and I am afraid to drive it too much with the hard shifting. It sounds like a loud thunk and revs higher than normal to shift. I have not taken off road nor has it rained. Just stumped on how to go about fixing the problem.


ANY and ALL help is GREATLY appeciated!!


James

simple stuff first
the od flashing and hard shifting
its telling you yep something is amiss, hard shifting is the tranny limp home or protect mode, it ramps up line pressure and dleays shifts, which usually means they are hard and abrupt
first bet would be to the rear sensor on the punkin that measure speed, (vss senor) most common to go bad. drop in an autozone and have em read the codes...
vss sensoer takes about ten minutes to change.
also with the age of the truck it might be covered in metal shavings, so you may be able to wipe it off.
has teh rear fluid been changed recently???

 

[deeretrac]

does your interior light work? also is the odometer working? if not check fuse #8 or # 9 cant rember which, if blown it will cause your problem.

happens to me about every other washing of truck.

Rob

 

[JOAT]

Don't guess, if the fuses are all good, get the codes read. Alot of things can cause that pesky limp mode.

If you need to drive it that way, start out in manual second and shift up around 35mph. Takes alot of the jolt out of the shifts.