i have a 94 ford f250 turbo diesel, and i belive the trans is a c6, and when i floor it, it shifts hard and to get it from third to overdrive i have to let of a little to get it to shift into overdrive. idk why. is it about to go, i have increased the shift timing but it still did that before i did. help! please! lol

 

94 would have the E4OD trans....3 plus OD.....the C6 is a 3 speed and special order.

You increased the shift timing....????? how did you do that, do you mean reset the FIPL sensor as below.

To set to specs:
With a warm engine and the idle speed set to your engine specs probably 650 in drive (curb idle).

Now with key on engine off. First connect the negative lead of a volt meter to the negative battery post, then place a paperclip straightened to slide up the side of the center wire for a good contact, touch the positive lead to the paperclip. Electrical connector must beconnected to the FIPL.

If your FIPL requires resetting loosen the small torx screws and attempt to attain the correct setting. You can loosen the large bolts on the bracket if necessary but try to retain the centering on the FIPL/blade.

Your trying to get closed throttle voltage: 1.1 V, wide open throttle voltage: minimum of 3.8 V but not more than 4.3 V.

If you can attain those #s then tighten the screws/bolts and ensure the voltage is at the correct setting after tightening. You can also do a slow sweep of the fuel lever from idle to WOT to see if there are any blanc (dead) spots, much easier with a really $$$ meter with capture mode. If you still find there are hard shifts or very soft slippery shifts you can adjust to suit your driving but be warned slippery shifts will burn the trans up.

 

The C6 is a three speed auto, you have the E4OD automatic. Its computer controlled, and requires a specific setting of the sensor on the IP, if you changed that it will probably cause a fault code (flashing light and hard shifting). If I understandy you correctly, it is shifting hard in every shift, except 3-4?

How many miles on it?

When did it start doing this?

Edit: PLC, you beat me by 1 min.

 

i adjusted the shift timing by moving a black thing back on the injector pump. idk??? some diesel mechanic told me to try it.

it actualy shifts hard in all gears, it has always, since i bought the truck about 3 months ago, the guy who owned it before me had the trany rebuilt, idk to what extent but mabe the hard shifting is due to a tight transmission? ive been told that hard shifting means it will blow out soon, is this true?

oh and i increased the shifting for more mpgs, lower rpms, and it seems to work because before i did that it would shift at around 2500rpm at almost all gears. i think the previous owner did this because it was a work truck and he towed alot, so shifting at a higher rpm gave more hp output while towning.

 

Do the FIPL setting on my last post but consider the info below......


DIESEL FIPL SENSOR INFO
DATE 1992
REASON
Early Black FIPL has High Failure Rate
RECOMMENDATION
Always replace the black colored early FIPL or any colored FIPL having 60 thousand or more miles with the late gray colored FIPL.
PART NUMBER
F2TZ-9B989-C

 

Adjust the FIPL, Then change all the fluid, including the TC. Install a good transmission cooler and gauge even if you dont tow alot.
Change the fluid every 15-20K OR when it get too hot. These things NEED clean cool fluid.
If your trans is origional, start saving to have it rebuilt, there are several MAJOR upgrades that have been done over years on the E4OD.
Mine is built to 4R100 specs now. It has been apart 2x since I've owned it. The last time was because of a broken torque converter. I have a triple disc now.