94 f150 E4OD shifting problem
#46
08-05-2012, 01:47 PM
#48
08-05-2012, 04:26 PM
#52
08-06-2012, 06:31 PM
Block the wheels and put the E4OD in Neutral.
Take the nut off the shift arm at the E4OD and pry it off using the heads of the two screws that hold the sensor on as a pivot point.
Loosen the two screws that hold the sensor on.
Twist the sensor until the two lines line up.
Tighten the two screws and check that the two lines are still lined up.
Put the shift arm back on the shaft with its nut.
That is about all there is to it.
Good luck.
/
#53
08-06-2012, 09:39 PM
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#54
08-07-2012, 12:52 AM
The transmission in these trucks is "dumb". There is no shift logic built into its hydraulics, It's entirely controlled by the computer.
What was the old transmissions doing before it died, and how long was the truck out of commission?
One thing I haven't thought of, is that the early E4OD solenoid packs had back-EMF protection diodes built into it, while the later ones do not. Basically when you turn a solenoid off, the magnetic field collapses and generates a large high-voltage pulse on the circuit. You put a diode on backwards across the circuit, and it will prevent the high voltage pulse from damaging sensitive circuitry - like the computer. 89-94 E4ODs had the protection diodes built into the solenoid pack, while the 95-97 E4ODs did not - they moved the protection diodes into the computer.
Using a late model E4OD on an earlier computer (which you are doing) has the possibility of damaging the computer. This is quite possibly what happened.
What was the old transmissions doing before it died, and how long was the truck out of commission?
One thing I haven't thought of, is that the early E4OD solenoid packs had back-EMF protection diodes built into it, while the later ones do not. Basically when you turn a solenoid off, the magnetic field collapses and generates a large high-voltage pulse on the circuit. You put a diode on backwards across the circuit, and it will prevent the high voltage pulse from damaging sensitive circuitry - like the computer. 89-94 E4ODs had the protection diodes built into the solenoid pack, while the 95-97 E4ODs did not - they moved the protection diodes into the computer.
Using a late model E4OD on an earlier computer (which you are doing) has the possibility of damaging the computer. This is quite possibly what happened.
#55
08-07-2012, 12:14 PM
Elder User
One thing I haven't thought of, is that the early E4OD solenoid packs had back-EMF protection diodes built into it, while the later ones do not. Basically when you turn a solenoid off, the magnetic field collapses and generates a large high-voltage pulse on the circuit. You put a diode on backwards across the circuit, and it will prevent the high voltage pulse from damaging sensitive circuitry - like the computer. 89-94 E4ODs had the protection diodes built into the solenoid pack, while the 95-97 E4ODs did not - they moved the protection diodes into the computer.
Using a late model E4OD on an earlier computer (which you are doing) has the possibility of damaging the computer. This is quite possibly what happened.
Using a late model E4OD on an earlier computer (which you are doing) has the possibility of damaging the computer. This is quite possibly what happened.
You certainly have my respect.
Bob
#56
08-07-2012, 12:28 PM
#58
08-07-2012, 02:21 PM
#59
08-07-2012, 05:10 PM
Elder User
I checked the PSOM visually and found no signs of any problems. everything looked really good. Then i checked my PCM and it looked perfect. but it had no electrical compacitors in it like were showed in the picture that was posted.
This is a little disturbing and may be a clue as to what is and was going on. To me, it sounds like his "origional PCM" was the wrong year for his truck.........causing electrical damage or a mismatch somewhere ???????
I bought a PCM out of a 93 f150 with the same motor and trans and it had 3 electrical compacitors. is there a diffference in the compacitors and such in a 94 PCM than in anyother one?
im still dead in the water, its still having problems and i dont know whats causing it. i took it for a drive down a 2mile mile road and held a constant speed and throttle and the truck was constantly shifting between 3rd and 4th. whats causing that?
This is a little disturbing and may be a clue as to what is and was going on. To me, it sounds like his "origional PCM" was the wrong year for his truck.........causing electrical damage or a mismatch somewhere ???????
I bought a PCM out of a 93 f150 with the same motor and trans and it had 3 electrical compacitors. is there a diffference in the compacitors and such in a 94 PCM than in anyother one?
im still dead in the water, its still having problems and i dont know whats causing it. i took it for a drive down a 2mile mile road and held a constant speed and throttle and the truck was constantly shifting between 3rd and 4th. whats causing that?
Bob
#60
08-07-2012, 06:15 PM