Hello all and thank you for keeping this forum alive with your participation. I just want you to know that I've been reading and learning about my truck for months because of all of you.
I have exhausted all possible options for my 94 E4OD SLAM-shifting transmission. A battery cable remove-reconnect, results in truck shifting smoothly until I hit about 60mph, and then from that point, next full stop will result in slam shifting throughout all the gears. It shifts at the right speed points, but it shifts really hard.

So far, here is what we have done;
- Replaced VSS (non Motorcraft, 1300 Ohms)
- Replaced TPS (Calibrated to 0.985V at idle, smooth Voltage sweep to 5V)
- Replaced MAF (non Motorcraft)
- Replaced MLRPs (and new plug, non Motorcraft)
- Replaced Radiator, ATF (Merc 5), Fluid + Filter (twice)
- Replaced Trans Valve Body (rebuilt RockAuto)
- Replaced Trans Solenoid pack (Rebuilt RockAuto, still have original)
- Replaced PCM (yard, but same "HOG0")
- Replaced PSOM (sent it out for rebuild to Module Mechanics, square wave tested.)
- Replaced Radiator (thought maybe blocked Trans cooling lines?)

The truck engine otherwise runs smooth, many of above parts fixed the jumping (or dead) speedo, detonation, fuel mileage (TPS), occasional no-start issues (MLRP,) and a myriad of other well-documented problems. But the super-hard-shift problem remains.

Most strangely, after battery-disconnect reset, the transmission will shift perfect until I get out on the highway and hit about 60mph, even downshifts/upshifts/OD on highway are fine, but once I get off, hard shifts return.
During recent snow, I drove slower-than-highway speeds (>45mph) and after a couple of days driving at these lower speeds (~40 miles or so,) transmission shifts smooth! Snow melted, speeds increased, the hard shifts returned.

OD light is not flashing, there is no dashboard warning lights (and they all work,) and Engine running codes return 111. How long do the codes take to set?
We tried tracing the wiring, found nothing remarkable - but to be fair - we didn't check every inch, as many wires still inside the untouched factory loom.
Mechanics and Transmission places I spoke to say it sounds like an electrical issue, and they all suggested same as what I have been reading here: TPS, MAF, VSS, MLRPs, PSOM, even PCM...

Any fresh ideas? We have a garage and a lift at my buddy's house, so..
I thank you all in advance.

 

Transmission/VSS codes are only displayed as Stored Codes in Continuous Memory not KOER. Yes you can have a stored code without a Check Engine Light (CEL) or a flashing O/D light. Run the Key On Engine Off (KOEO) tests and Stored Code display to verify what is triggering the computer to go into limp mode.

 

Tracing wires is just a way to waste time. It doesn't do anything useful. Wiring MUST be check electrically to do any good. But what would you be looking for? You haven't checked for KOEO codes to know what to look at. Run KOEO (Key On Engine Off) self test and see what codes are stored. Then you'll know where to start looking.

 

Thanks for replies guys.
At first it flashes 1-1-1---1-1-1 --------1-- first 30 seconds or so..
Then, two digit codes: 62 86 28. Or is that 628 628?
Here is the video, if you'd like to watch yourself. I am no expert.

 

That appears to be 628. And appears to be in memory. Excessive torque convertor slip.

 

Even though the trans is not slipping, ever? I feel the TQC engage at around 35mph (light throttle,) .. stay engaged, even through 4th, during highway drives.. No shudder or anything like that.
What do you suggest, a new Torque Converter?

 

Mark or rla can better answer that for you. Let's see what they have to say.
I will say that if it is a memory code it means the code is not currently active, but it has happened. Look at what rla said about limp mode.
You can also Google Ford limp mode for a more detailed explanation.

 

Mark K is the transmission expert. Now that you have a code to work with he can help guide where to go in the troubleshooting path. If it were me I would start by removing the solenoid pack connector then inspect it for signs of moisture, fluid, and worn wires. Quite a few relatively recent posts where it was found the wires to the connector were bare.

 

Exactly right.

The transmission is slipping every time you get above 60 MPH. You said so (indirectly) in your first post in this thread.

Can you feel 50 RPM of slip in the trans? I can't, I had had instrumentation that could show me when it was happening, but I still couldn't feel it. Either could anyone else I worked with in transmission engineering at Ford. It is so little slip that it has no feel to it. But it can destroy the trans over time, so the code is designed to set when there is at least 50 RPM of slip over a couple of seconds.

That is likely to be what you need. If you look at the front of the converter (the side facing the engine) does it have a blued look to it? Or does the converter have a uniform color all over? If it is blued it is from excessive heat from slipping and needs to be replaced.

 

In my GM cars, wiht a 4t65e, 3 of them so far, I have drove with a tech 2 watching engine revolutions, ISS readings, and the difference calculated real time. There the Torque converter is designed to slip a certain RPM in order to reduce chuggle and they also have an electronic converter clutch to reduce losses at lower speeds and stuff, but the point being that when driving, normally, you NEVER would feel those 50rpm, often a little less but ive seen it at 50rpm, slips, because that was designed that way presumably because its not detectable. Also, being a smaller trans, smaller converter, and being designed to do this I guess it would transmit less torque so maybe it explains that BUT it goes to show that you are correct about feeling 50rpm slip.

And being the E4OD doesnt have a pwm converter like a 4r100(I think?) Its not meant to have those slips but rather ON/OFF behavior. I can only imagine a ON/oFF lockup in a 1994 transmission is just as bad as it was in a basic lockup converter from the 80s whenever ford transmissions got them (Like TH350c for GM vehicles).

One would think, well, 50rpm, it cant hurt that much, but that would only be right if you are talking about pre lockup converters which wasted lots of energy but they also were being rebuilt in relatively low mileage intervals compared to 1994 e4ods. My old 77 LTD had 70000 or so miles on it with a rebuild at 64k on its C6 in 1992. Albeit it was a long distance cruiser and weighed 5200 pounds but still.

Winded stuff aside, The OP Shouldnt rely on physical feeling of slipping to discount the transmissions diagnostic since the parameters for setting it are hard to oopsie based on how its not widespread setting incorrectly and your thread is about hard shifts, possibly as a result of shift times being excessive so maybe line pressure is being used to shorten them ? Just a thought

 

Mark being he has a 94, pre the good quality of life changes in e4od, but also not the touchy years early on, could he possibly have somethign that caused this issue, such as a restricted cooler or insufficient flow which was fixed with larger diameter lines in 97 or 98 maybe 99 iirc?

I know my cooler had minor restriction that I fixed with air duster and pulling the top line off. But I know that the lines leading back to the e4OD make a sharp bend when they 90 degree angle upward toward the ports on the radiator. I can see the line is partially kinked and i mean partially, where if the transmission mount would be worn enough or a enough deflection from torque or me bumping it I could probably put a restrictive bend in it. I was thinking personally about using a tubing cutter before and after the bend a sufficient amount to place a hose in to 1) prevent the concern 2) keep pulses/absorb energy from vibrations better than metal hardlines alone maybe? I also should realistically put the larger diameter lines in, but notwithstanding.

I also remember something about checkballs in the cooler lines but I forget exactly what about them or what it was related to, but Regardless of whether his torque converter needs change, i would personally check to see if there maybe is a cause. to my knowledge the lines either feed to or come directly from that flow?

for reference, if you remember my username, im the one who had puking transmission fluid and type F from a time long past. Never had any trans codes so thats good, but Im sure overheating that many pukes wasnt easy either. ive monitored the temps since and they have stayed substantially lower Truck works ok as it stands with proper fluid. Im working on clearing a slot in the garage to do pan drop fluid and filter.

 

The E4OD is on/off, and the 4R100 had a PWM. But the PWM was not used for continuos slip in the 4R100. It was used to better control the on/off behavior.

Ford had continuous slip in 1994, just not on the E4OD. The AX4S and the 4R70W both had it.

The harsh shifts are due to the 628 code being set. Once that code is set line pressure is set higher to prevent further transmission damage. That causes harsh shifts. When he cleared the codes the failure mode effects are erased.

The 4R100 had larger cooler lines than the E4OD. Smaller cooler lines only affect cooling, not the torque converter operation.

There is a checkball the cooler bypass, but there are no checkballs in the cooler lines. If the checkball isn't working the coolers will be bypassed and the trans will get hot. The converter operation will be unaffected.

 

Thank you all for your responses. I will replace the TQ Converter. Then do battery reset after.
Any particular brand, or type of converter, what do you recommend? I was thinking just ordering it on RockAuto...

Thanks in advance. This is really helpful.

 

thanks fam youre the bomb.com

 

hold your horsies there mr. you want to confirm visually that youre looking at a converter issue which only takes a few minutes under the truck. as likely as it is, you dont want to rely on people saying thats your problem to then find out its something else no one could possibly conceive of etc. At least look at it for a learning experience kinda thing.