I have a '90 E350 with 7.3L diesel. It used to shift fine, but the torque converter failed. I took it to the "best transmission shop" and had them repair with all the updates, a premium torque converter, and a high capacity oil pump. Since then the shift points are about twice fast as they used to be, for example, the 4-3 shift (coasting) occurs at about 38 mph instead of about 20 mph. All the shifts are at much higher speeds. The shift points might be OK for a gas engine, but are too high for the diesel.

I need to get it to shift at lower speeds as it did originally. One solution I thought of would be to hook something in the speed sensor circuit to fool the computer into thinking the speed is higher than actual. Any other ideas? Thanks.

Joe

 

The shifting speed is conrtrolled by the PCM and the PCM decides when to shift based on inputs from the TPS, speed sensor and MAP sensor (gas only). If an E4OD is shifting too late then I would suspect that it has a code in it. Have you had it scanned? Or taken it back to the transmission shop and asked them about why it is shifting to late?

If the TPS and speed sensor are OK then you need to see if its the PCM that is commanding the shifts at that speed.

I suspect that either the PCM has a code (which is causing the PCM to shift late) or there is an internal problem that is causing it to shift late. If the PCM is commanding the proper shifts then you probably have a low line pressure condition which won't let the transmission shift until well after the command so it can build up enough line pressure to actually execute the shift.

Either way, you need to talk to the shop that rebuilt it.

Steve
'95 Clubwagon XLT

 

I took it back to the transmission shop three times. (I never went back after the third time as I did not want to go to prison for murder.) Each time the head guy would drive it and say that it was shifting fine, even though the engine was screaming (for a diesel) before shifting to the next gear. He claimed that the fuel lever position indicator needed work, but would not do it as he had "already spent too much time on it". I replaced the fuel lever position indicator and adjusted it many times trying to get it to shift right with no changes in the shift speed problem, mainly it affected downshift under load. I've also replaced the speed sensor (the one one the transmission, not the one on the rear axle). All this seemed weird as it shifted fine before.

At one point it quit shifting, and I found that the computer had come unplugged. It started shifting again when I plugged it back in, but no change in the shift speeds. It made me think that they had switched my computer with one from a gas truck, but I have no may to know.

The Ford dealer wants a lot to check it on their computer, and I know from past experience that they double what they charge for diagnostics if you don't let them do the repairs. Is there some inexpensive way to get the codes, if any?

 

Sorry to hear about your trouble. I have always wondered how shops that treat customers that way stay in business. It sounds to me like there is a problem in the transmission as you can't swap the PCM for a gas motor and have it run.

Is the OD cancel button flashing the "off" light? That's how it indicates there is a code. You can have any shop scan it. Someone should be willing to pull the codes for $20 or so. Or you can buy a cheap scanner at Autozone/OReilly's/Advance for under $50 and do it yourself.

I suspect that eventually you are going to have to have a transmission shop solve the
problem.

Steve
'95 Clubwagon XLT

 

It sounds like the guy rebuilt it with the parts for a gas motor. That or the front pump is loose causing low line pressure.

 

The OD light doesn't flash. Does that mean there are no codes to retreive?

As far as transmission shops go, the one I went to for the work was recomended by several different friends and neighbors as the best transmission shop around. I've talked to other shops and they don't seem to know much about E4ODs. That just leaves the Ford dealers, and they probably don't know anything either, but will charge more for it.

I was told by the parts guy at the Ford dealership that there are no differences between gas and diesel E4ODs, even the ratios are the same. There are some aftermarket torque converters designed for diesels, and I paid more for one of those. The oil pump was also a high volume pump that I paid extra for.

In what way could the pump be loose? It doesn't leak. Would a problem with the pump also cause it not to move for a bit when shifting into reverse when first starting in the morning?
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The higher capacity oil pump is causing a higher line pressure in your tranny that's causing different shift points. There are several transmission reprogrammers for sale for about $30. But I don't think they're going to help you as your line pressure is already higher. I would talk to the owner of the shop, tell him you're going to invoke the 'lemon law' (even though there is no such thing, he will probably not know this). I would also befriend a local attorney to write a letter for you to send to the business stating you spent your hard earned money in good faith and now, blah, blah, blah. Then talk to the Better Business Bureau in your area. True the BBB can do nothing, but every business owner (the legit ones) do not want a complaint from the BBB on their record. You make enough noise, and someone will respond. Start making some noise, or else no one can hear you, Ken

 

It sounds like the best shop there trained under a ford dealer. If it worked before it should work now. If it is a diffrent torque converter from spec. it could be that it is more for a high RPM engine like for truck pulls or what ever. But the one that put it in should know that. Standing on the brake will the engine rive higher than it did before?
Some times things are better left alone.
Wink

 

The torq converter does a couple things; it acts as a clutch so the truck can idle at a stop, and more importantly, it multiplies torque and sets engagement rpm. Diesels make more torque lower in the rpm range, so you want the torq converter to engage at a much lower rpm. A drag car for example may have the stall speed, which is the highest rpm the engine will run to while in gear, set to maybe 4,000 rpm. So you can sit at the starting line lights, foot on the brake, car in gear and rev the motor to 4,000 rpm til the green light, take your foot off the brake and go while the engine is in it's optimal rpm. A diesel torq converter should engage at a low, low rpm, because that's where it's engine is most powerful. This guy had a diesel specific torq converter installed to take advantage of his engine characteristics, it should function better. But I think the high pressure pump is causing shifts at a higher rpm, which is not what you'd want for a diesel. Normally a trans chip raises the fluid pressure, which gives as gas guys higher shift points. Ken

 

Hey Ken that was what I was trying to tell him.But down here we think in truck pulls,
mud boggs and swamp racing. So any way if he be city boy or country red neck the point is that that premiun torque converter may be where he is getting the high RPM.I don`t know how the electric would act with a stall converter. But could be that it is down shifting that unless the converter is staying locked up it may be from the difference in drive shaft and engine RPM that is messing with the computer brain as he was talking about down shifting. But I am just guessing. I have a EOD and a regular OD. And the EOD will do some strange things with just a little change in other things.As tire size.
Wink

 

When I couldn't get the transmission shop to make it right, I tried to get the credit card company to do a charge back, or whatever they call it, but they wouldn't do it. I did stop back at the shop recently and it is under new ownership. Apparently, the guy that used to run it was killed.

I had stopped at the shop after they had the transmission out and asked for a detailed estimate so I could deterimine what parts I wanted replaced. When I returned the next day at lunch they had already put it back together. The work order I was given just states "parts and labor $1913", and has nothing else that can be made out.

I specified a heavy duty torque converter with a low stall speed, but have no way to know what was installed. It does seem to slip more than the old one. The clutch engages, and disengages, but seems to disengage at only a small increase in pedal pressure.

If the pressure is too high, is there some way to reprogram a lower pressure, if that would make it shift at a lower speed?

 

I think Ken is right, if indeed they put a higher volume pump in it then the line pressure is too high and that could make it shift late. Too high a line pressure will also make it slip in lockup.

Unfortunately, if a transmission is screwed up after overhaul, it is often very difficult to diagnose the problem from symptoms.

Steve
'95 Clubwagon XLT

 

Wow, dude you are in a tough spot I'd say. But you do have options, even though the shop has a new owner (that sounds dubious, it takes a while to change ownership) you still have a case against the previous owners estate, or against the corporation if it was incorporated. But you really need to talk to an attorney in your state. If you signed a blank work order without specifying what work was to be done at what price I think you just paid for a hard earned lesson. If you asked for a different torque converter, and it was listed on the work order and you paid for the same, you will have to bend someone's ear, like the previous owners representative. If you went in and paid the bill sight unseen and there isn't any of what you asked for on the work order you were given (you did sign it didn't you ?) you probably have got nothing to go on. Good luck bro, I feel for ya, Ken

 

The transmission work was done about three years ago. I did contact three lawyers, but none wanted to do anything. I did not sign the work order as I did not get an estimate. When I went in the next day after asking for an estimate, they had already put it back together.

I've been trying to find a way to get it to shift right since but have not found a knowlegable transmission tech. Is there some way to lower the pressure to see if that will cure the problems I'm having?

 

Come to think of it it sounds like it is set up for a gas burner. I have a 93 F-150 and it down shifts at between 35 and 40. It is and OD my van is a EOD and it is hard to tell where it shifts.
Wink