Hey All
My truck Info:
-1997 F350 Cab Chassis 7.5L Dual Rear Wheels
-EEC-IV (No not OBD2, heavy trucks were exempt at the time)
-4R100 Automatic with external spin on filter
-Truck runs beautifully
-No engine light on

Some info on the problem:
-I get in and start it up, put it in Drive, Take off and it just starts shifting to random gears/skipping to high/lugging.
-If I Shift it manually 1-2-D it works perfectly fine, no slipping, nothing unusual.
-Cannot make it shift down with the accelerator pedal
-Overdrive button works properly and no flashing OD light.

Here's the fun part:
-After driving for a bit (Maybe 15 mins or so) it starts working perfectly, Shifts smooth and properly, down shifts properly when i step on it to pass or climb a hill
-If I shut the truck off for a few hours I can hop in and take off normally it works perfectly
-If I leave it sit overnight then go to use it again in the morning it's right back to shifting crazy.

Here is a bit about what I've done so far:
- I thought maybe the keep alive memory power to the PCM wasn't there so I verified it is and its the same voltage at the battery.
- Replaced Throttle position sensor with ford genuine part and also verified the ground, 5 volts, and signal. Also verified no resistance in the TPS wire to the PCM
- Replaced the speed sensor on the rear diff (From what I can gather this is just for ABS purposes? But I changed it anyway) I have no ABS light on and didn't before either
- Replaced the PRNDL switch on the side of the transmission and double checked the alignment. Starts fine in P or N and reverse lights work. Before I had to jiggle the shifter to get reverse lights to work.

What I have not done yet:
- Replace the speed sensor on top of the transmission (this model doesn't have the one on the extension housing) My speedometer does seem to hop around up and down about 10kms/hr when cruising on the highway so I'm thinking maybe this could be the culprit.
- I saw a youtube video of a guy having similar problems and he seemed to cure it by installing a new plug on the transmission solenoid harness...but where mine works fine after a while I'm not sure theres an issue there. I can't see it yet because of the location of the exhaust. The only thing I can think of is maybe when the exhaust gets hot it helps make the connection.....? Grasping at straws at this point.

If anyone can provide any insight I'd very much appreciate it. I don't use this truck much but when I need it I need it.

Thanks

 

are you sure that’s a 4r100?

a 460 would have come in front of a e4od, the direct predecessor. I don’t think the eeciv could control the pwm converter
unplug the rabs unit behind glove box and see if your issue with speedo still happen

 

I'm pretty sure it's a 4R100 either that or a really beefed up E4OD (has the big deep pan etc like the 4R100
Seems like everything about this truck is weird being a 97 and still EECIV etc.

 

What year is the 4R100 that you installed? Ford didn't build the first 4R100 until 1999, so your truck left the factory with an E4OD transmission. Another way to tell which trans you have is that the 4R100 was never built with the 460 bolt pattern. So if you have a 4R100 the bellhousing has been modified or an adapter plate was used.

The keep alive feature wasn't used by the transmission in 1997. It doesn't matter if the keep alive works or not for transmission function.
Not only ABS, but to schedule all shifts. This is one of the main sensors that is used to decide when to shift the trans.

Your speedo reads the sensor on the rear differential, through the PSOM located on the back of the instrument cluster. It is likely that the PSOM is causing an erratic vehicle speed reading.

To check this, get Forscan at www.forscan.org. With this tool you can see what the PCM sees for vehicle speed. You can also read all codes that are set.

If you really have installed a 4R100, there is a speed sensor on top of the transmission. Your 1997 PCM can't read it, so it doesn't matter if it is any good or not. If you have an E4OD, and I think you do, there is no speed sensor on top of the transmission. Ford never built one that had a sensor at the front but not one at the back.

Have you tried reading codes? I know you said that the OD light isn't flashing, but there still could be codes there.

 

I must be mistaken about the 4R100 I guess I didn't think the e4od had the deep pan with a drain plug which is one reason I thought it was a 4r100

I'm going to test the wiring for the speed sensor in the diff too.

I've done some further reading about the instrument cluster possibly being the problem as well as possibly the tone ring in the diff.

I'll check the codes, I also found this afternoon the engine light may be burned out because it doesn't ever come on even during lamp test. Previous owner may have even removed it. There are some codes stored as I checked with a test light. Dark here now so I'll continue tomorrow getting the codes.

Thanks for all the input so far.

If I post photos of the transmission would that identify it for sure?

 

It is an E4OD. The only automatic available in a 1997 F-350 was the E4OD. There is no other possibility.

The 4R100 pan will fit an E4OD.

 

Did you say a deep pan? Im not at all certain, but if the pan is deep and your truck is 2wd, that to me is grounds to question if the dipstick is the right one for your truck, but its not a universal rule that deeper pan = needs a different dipstick, but im unsure if that applies here. basically, you could have a massive fluid deviation from proper spec if that was the case.

Also, if the PO who changed the pan out did NOT also use a 4wd filter............

Yeah.

 

The dipsticks are the same for 4x2 and 4x4 pans, also called shallow and deep pans. The level of fluid is the same in both transmissions, but the 4x4 has more fluid under the pickup tube. You are correct that there are two different filters. If you have a 4x2 (shallow) filter in a 4x4 (deep) pan you will suck air at times, and the filter is likely to fall out. A 4x4 filter will not fit in a 4x2 pan.

 

I don't think it was changed. The truck came to me like that and others like it that I've looked at have the same. It's an ex-uhaul..I wonder if maybe they custom ordered a different version of the E4OD.. Has the big pan and also a spin on external filter in the cooler line.

 

It seems FORscan is only for OBD2 compliant vehicles

 

Ok, A bit of an update.
-Unplugged the RABS module to rule that out causing interference or something - The bouncing speedometer went away.
-Metered out the wiring between the PSOM and VSS in the diff, it's fine. Diff VSS meters out fine and is new ford replacement
-Metered out wiring between TPS and the pcm, meters out fine. TPS tests within range. (TPS is also new ford replacement)

The wiring all tested fine so based on some info on this thread so far I swapped out the PSOM - Same thing, worked like crap then started working fine the rest of the day. Next morning back to the same problem.

So it seems I've ruled out the PSOM, VSS and TPS

Got around today to reading the codes after putting a bulb in the CEL-

First round of codes: 63, 36, 21
Separator Flash
Second Round of Codes: 332

I haven't had time to drive very far yet, is there any kind of learning period after changing the PSOM or should it just work if that was the issue?

Where to go from here? Could the PCM be bad?

 

You will not have two digit codes with that year Truck.

 

Why not?
They are indeed 2 digits... They were repeated twice on the light flashes so I know there's no mistake.

 

More than likely your codes are 633 & 621. As subford said, you should only have 3 digit codes. You will not and can not have both 2 and 3 digit codes.
633 & 621 are both transmission codes.

 

Ok I'll go out and check again