E4OD revs in drive, unless overdrive is turned off

[mccall52]

Hello,

Came home with a 'new' truck yesterday. (About to update signature line, oops.)

During my test drive prior to ownership, I noticed the truck will drive just fine with the OD switch set to 'off', and it would have the nicest three gears I've felt in a truck.

Turn OD 'on', no so much. Truck will not accelerate from a stop, just revs. When cycling the OD switch 'on' and 'off' in drive you can feel the truck bump in and out of engagement, similar to what you would feel when you put any transmission in drive from park or neutral.

Feeling comfortable enough to drive it home 35 miles, I was quite happy with it. With a 3.55 rear axle, it was turning 2k RPM @ 55MPH (overdrive off, of course). Not sure when, perhaps after some traffic lights, I noticed my RPM @ 55MPH increased to around 2250-2500. A short time later I noticed my OD light was flashing. It was still shifting 1-3 nicely as described, so I kept on.

Decided to stop for lunch a couple miles from home, shut off the truck (mistake). Came back out, OD light flashing right after I started the truck. 'This is different', I thought. Can't select OD 'off', of course. Had to drop the selector lever into 2nd and nurse it home.

Later in the day a buddy came over to look, took it back out on the road, original scenario returns, no OD light flashing. Using a snap on brick scanner, I retrieved code 62.

This morning, I ohmed out all of the wires from the solenoid pack to the trans ECU, they all tested great, under an ohm of resistance. Solenoid pack connector tab is damaged, traces of transmission fluid. Old dielectric grease on both ends. Grounded the signal pins of the trans harness for each solenoid, can be heard to 'tick'.

It is my understanding I should replace the solenoid pack pigtail, clean both ends of the harness to a shine, and replace an O-ring because of the seepage. Is there anything else I should check first, and/or am I leaving anything out? I appreciate your help.

 

[SLC97SR5]

Unfortunately I don't have any suggestions for you but it is great reading about someone troubleshooting their issue and not simply wanting to be spoon fed the answer. Good luck!

 

[mccall52]

Thank you for your encouragement. I have since found some helpful documentation that is leading me to believe there is an internal failure of some sort. I found the following document extremely helpful:

http://www.transgo.org/Research/TechData/ford-t/TPgs/8th-E4.pdf

Condition #14 under the heading Quick Find Complaints and Causes describes my situation verbatim. I now have to get back on the road to divvy down the other conditions as described in the troubleshooting tree.

I wasn't excited about the idea of pulling the transmission, but I went into the truck deal with my eyes open, OK with the fact that I may have to tear into it. I'm game for performing any repair as long as I'm fairly confident the solution will hold water. I'll let the forum know how it goes.

 

[direwulf23]

I'm having very similar problems. I changed the tranny filter and fluid (well, I didn't do a full flush) and that seemed to help a good bit. Near as I can tell it's related to heat, but I still haven't resolved it. I do not think there's a mechanical problem

1994 Ford F250, 2wd, 7.3L IDI, NA, E4OD

 

[mccall52]

Hello Direwulf,

You do have a valid point. I need to make sure the filter element hasn't come apart and a piece clogged in the solenoids or somewhere in the valve body. In the next day or two I'm going to do that troubleshooting test drive and then drop the pan.

 

[direwulf23]

Oh, I also took my solenoid pack out and cleaned it up and the connector. In my very amateur opinion my problem is the tranny isn't cooling right (that seems to be the only consistent factor when it happens, I've been driving a fair while) and/ or the solenoid pack is faulty

1994 Ford F250, 2wd, 7.3L IDI, NA, E4OD

 

[mccall52]

Good morning,

Thursday evening I finally got the truck on the road for a test run. If you wait until it shifts into third, then turn OD 'on', the transmission will shift into overdrive. About 1500RPM @ 55MPH. I think the convertor clutch is locking up, not real sure. Anyway, if you kick it down for a upshift, it does flare up pretty bad, the tach needle will get into the yellow before it catches third. I drove like this for 2-3 miles performing diagnostic steps, figured for sure I'd get a flashing 'OD' light, never happened.

My next steps are to drop the pan to check for debris. Maybe I'll get lucky and the filter element will have come apart or is laying in the bottom of the pan, etc. () While it's apart I'll do some bench testing and inspection of the solenoids and air test the pistons.

 

[trackspeeder]

Good morning,

Thursday evening I finally got the truck on the road for a test run. If you wait until it shifts into third, then turn OD 'on', the transmission will shift into overdrive. About 1500RPM @ 55MPH. I think the convertor clutch is locking up, not real sure. Anyway, if you kick it down for a upshift, it does flare up pretty bad, the tach needle will get into the yellow before it catches third. I drove like this for 2-3 miles performing diagnostic steps, figured for sure I'd get a flashing 'OD' light, never happened.

My next steps are to drop the pan to check for debris. Maybe I'll get lucky and the filter element will have come apart or is laying in the bottom of the pan, etc. () While it's apart I'll do some bench testing and inspection of the solenoids and air test the pistons.

If you have a shift flair in fourth your converter isn't locking. Fourth is on or off.

With the old school TCM, you can test converter lock up by placing your foot on the brake peddle in fourth gear.

 

[mccall52]

Thank you for your reply. Sounds like I need to get it back out for another road test.

Just out of curiosity, I was getting the impression the flare up was happening after coming out of fourth, like third wasn't getting pressurized quick enough. The only time I've experienced flare up is during a kick down out of overdrive, with the exception being my original post.

I understand a slipping converter may blue the torque converter housing if it overheats enough. Sounds like I should be able to pull the bottom cover and look. I appreciate your help.

Edit: Do you mean by your response that the converter is locked anytime the transmission is in fourth? Also, can you recommend a good torque converter if that's the direction this heads? Nothing terribly expensive, I plan on leaving the truck mostly stock.

 

[trackspeeder]

What you're feeling during down shift is the converter staying unlocked.. That will give you the flare feeling.

The only way to see any bluing of the converter is to remove it. Inside the studs you will see a very distinctive ring. usually you will get a waning before that. A nice chatter when in fourth gear. Sometime you will get that in third during lock up. At this point the converter is dead.

The tranny will lock most of the time in fourth. If the RPM and or speed drops below a certain point the converter will unlock. The converter will unlock if you smash the go peddle to the floor.

www.racerxusa.com

 

[mccall52]

Thanks again for your prompt response. Any chance this could be related to my original issue of not accelerating from a stop when overdrive is on?

 

[trackspeeder]

Thanks again for your prompt response. Any chance this could be related to my original issue of not accelerating from a stop when overdrive is on?

That might be another issue. Starting in a higher gear will give you a "not accelerating" feeling.

 

[mccall52]

Dropped the pan earlier, no bits lying in the pan like I had hoped, but the magnet looks like a donut because of all the debris picked up. I'll let everyone know what is torn up once I get the transmission out and apart. I won't go back in without a new torque convertor. Thanks for everyone's input.

 

[direwulf23]

That's about what mine looked like. I'm personally concerned it's a torque converter problem.

1994 Ford F250, 2wd, 7.3L IDI, NA, E4OD

 

[mccall52]

Got the transmission out, and pulled out the front half. The overdrive sprag has come apart as I suspected. Sprag races will need to be replaced as well, and did a number on the surface of the planetary set, but should still be usable. Friction discs look good so far, steels have a few heat spots. I believe I've found where the debris on the magnet have come from. I'll get the back half out when I get it to the shop next week. Now to plan my build...

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