e4od

[big tom]

Hey you guys, first post here, and looking to try to get my poor old girl back up and running right w/ out spending an arm and a leg! I have some wierd problems w/ her. It is a 92 f150 w/ a 5.0 4x4 and e4od tranny. The problem is that when it is warmed up it will erractically downshift to a lower gear and then shift back up to the next gear very hard. (is this slipping?) It mostly does it from over drive to 3rd and back, and it will do it over and over in a several second interval. It sometimes will do the same thing in lower gears while accelerating. I changed the fluid and filter and it seemed to help for a couple days, but now back to the same problem. I have stopped driving the truck for now and am hoping for some advice. It seems that if I use the colum and manually shift it there is no problems and if I turn off the od button I can drive it around. When I changed the fluid it seemd to be clean and red, however the magnet had a nice coating of goo on it. Anyone out there able to help?

 

[TexasNomad]

Welcome!!
Sure some body will come along that can help

 

[subford]

I think I would test the MLPS sensor on the side of the transmission. They have a habit of this kind of thing:

Here is the test:
http://i54.photobucket.com/albums/g91/subford/Transmission/ManualLeverPositionSensor.jpg

/

 

[blacksnapon]

Yep! MLP and water intrusion in the connector.

 

[SuperCab]

Welcome to the site, man.

 

[big tom]

Thank you friends, I appreciate the welcome and I will perform the test in the morning. Cheers!!!

 

[Skandocious]

Welcome! I think Bill and Vince are on the right track-- the MLPS sounds like the culprit here.

And the powdery goo on the magnet is normal if it has a decent number of miles on it-- don't worry about that.

But you say that if you turn off overdrive or manually shift through gears then the problem goes away...? It almost sounds like maybe the problem might be with your torque converter clutch (especially since it is only active at higher speeds/gears). Are you sure it's dropping to lower gears, or is it possible that the torque convert clutch is disengaging and reengaging?

 

[subford]

But you say that if you turn off overdrive or manually shift through gears then the problem goes away...?

When you turn off overdrive or manually shift through gears then you are taking the MLPS out of the picture or at least that is the way I understand it.

If I am wrong then I would like a correction on this point.

 

[big tom]

Welcome! I think Bill and Vince are on the right track-- the MLPS sounds like the culprit here.

And the powdery goo on the magnet is normal if it has a decent number of miles on it-- don't worry about that.

But you say that if you turn off overdrive or manually shift through gears then the problem goes away...? It almost sounds like maybe the problem might be with your torque converter clutch (especially since it is only active at higher speeds/gears). Are you sure it's dropping to lower gears, or is it possible that the torque convert clutch is disengaging and reengaging?

Thanks for the thoughts here, I appreciate it very much. What you have said here has really got me thinking about what the problem might be. I seems logical that what you are thinking here could be what is going on. The truck has 140k on the clock so it is no spring chicken! After I check the MLPS later today, supposing it checks out fine, how would one troubleshoot the TC? And I have to point out that I have not ever really worked on a automatic tranny, I have always had trucks and cars w/ manual so it is a little foreign to me, would the trans have to be dropped to replace the TC?

Here is more food for thought... The last time I drove the truck on the freeway a couple weeks ago (before I changed the filter and fluid) I was hauling a small 3000lb trailer and after about 15 or 20 miles at speed the problem was happening where it seemed to be downshifting and then slamming back into gear on and off for a few mins. I quickly got off the freeway and pulled into a parking lot to let it cool down and the truck stank of burnt clutch, just like a manual trans would if you roasted the clutch. I let the truck sit for about 8 hours and had someone else pick up the trailer.
I got it home on the back roads and changed the filter and fluid, and the problems were a lot better for about a week or so, but when I drove it home on Wed evening it was back to having major problems, but seemed to be ok w/ manual shifting. What do you guys think about that?

 

[subford]

Yes the transmission has to come out to change out the TC.

 

[Skandocious]

I didn't realize you said it was slamming back into gear... To the best of my knowledge, the TCC is not capable of making your truck jerk or slam when it engages/disengages. It's normally very smooth by the nature of the mechanism.

This sounds more to me like your TC is going bad... The burnt clutch smell could be your TC slipping and creating excess friction. Do you have a trans temp gauge installed? That would definitely give an indication... Hotter fluid usually means a slipping TC since the TC is the biggest source of heat (friction) in the transmission.

And Bill-- I'm not sure about the exact operation of the MLPS, but my assumption was that it is the sensor responsible for sensing which position the lever on the shift column is in, and telling the transmission what it found. In other words, the MLPS sees that you're in 2nd on the shifter, and tells the transmission "he's in 2nd, please adjust your shift solenoids appropriately". Again, this was just an assumption that I had-- I'll go check my Ford manual now to see how they describe the operation of this sensor.

Side note: Tom, what kind of fluid did you put back in, and how much?

 

[big tom]

Hey I put in mercon v and used about 6 quarts. I checked it a couple times since and the fluid level is right where it should be. I do not have a trans temp gauge...

So I have a question about the MLPS test. Do you test the pins on the actual switch, or do you test the connector that you pull off? I guess if you are testing the pins on the switch you would have to use a mirror to see it? I just had a quick look but the weather is bad here and I don't think I will be able to really look at it this weekend because I don't have a garage and we have 18" of snow right now.

 

[Skandocious]

Okay I just looked up the info on the MLPS in my Ford repair manual. They refer to it as a Transmission Range (TR) sensor.

Description:

Transmission Range (TR) Sensor
The transmission range (TR) sensor is transmission-mounted.

The powertrain control module (PCM) (12A650) monitors the voltage across a series of step-down resistors that correspond to the position of the manual control lever (7A256). The PCM uses this information in determining desired gear and EPC pressure.

The TR sensor permits the engine to start only in the PARK and NEUTRAL positions and activates the backup lamps in the REVERSE position. The sensor also contains neutral sense circuitry for 4x4 applications.

Here's you're first step before you start checking voltages at the pins:

Inspection and Verification
1 Operate the vehicle to verify the customer's concern.

2 Check wiring and connections for the transmission range sensor to find looseness, corrosion, damage or other obvious causes for a malfunction.

3 If an obvious cause for an observed or reported malfunction is found, correct the cause if possible before proceeding to the next step.

4 If the cause of the malfunction cannot be found by system inspection, proceed to the following symptom chart, which serves as a guide for further diagnosis of a customer's concern.

Basically you just want to insure that the connection is tight, and if it is, that there is no corrosion in the connector. If it checks out, pull the codes. It's possible that your transmission has thrown a code. If you get codes, refer to the following chart, else-- skip it.

If you didn't get any codes, remove the sensor and use an ohm-meter to perform the following tests. Note that you're only measure the RESISTANCE across the terminals so I don't believe there's any need for it to be attached to the truck:

 

[Skandocious]

If you've got the sensor on your workbench then you won't be able to read those wire colors, so here's a diagram to help with that. It says 4R7W transmission but I believe the connector is the same:

Unfortunately they list two different tables with for the same connector, so you'll have to match the wire 1 or 2 of the wire colors to the pins to figure out which one you have:

 

[Skandocious]

Hey I put in mercon v and used about 6 quarts. I checked it a couple times since and the fluid level is right where it should be. I do not have a trans temp gauge...

This part has me a little concerned... 6 quarts is FAR below the system capacity. When performing a fluid change you should drain both the pan and the torque converter, it sounds like you only did 1 or the other. Draining both should yield roughly 10-12 quarts of fluid (a few quarts are still leftover in the cooler + cooler lines. Also-- did you change the transmission filter?

That being said-- you're now running a mix of old Merc/Dex III and Merc V fluid. On TOP of that, I don't recommend running Merc V in old/high-mileage E4OD's. Ford recommends it since they discontinued their support for Merc/Dex III fluid, saying the E4OD is backwards compatible, but I've heard lots of horror stories from guys who made the switch on their Gen 9 trucks (ie, healthy transmissions taking a dump after 5k miles on Merc V fluid).

The Merc V fluid has added friction modifiers-- friction modifiers control the amount of slippage or friction in your torque converter. More FM's = more slippage. You can see how if you're transmission was not originally designed for the added FM's then it may cause problems. If I were you-- I'd drain ALL of the fluid (pan + TC) and replace it with a good dino Merc/Dex III fluid. That may fix your problem if you havent damage the TC too much.

 

[subford]

And Bill-- I'm not sure about the exact operation of the MLPS, but my assumption was that it is the sensor responsible for sensing which position the lever on the shift column is in, and telling the transmission what it found. In other words, the MLPS sees that you're in 2nd on the shifter, and tells the transmission "he's in 2nd, please adjust your shift solenoids appropriately". Again, this was just an assumption that I had-- I'll go check my Ford manual now to see how they describe the operation of this sensor.

I know what the manuals say but I was told as long as you do not use OD and manually shift the E4OD the MLPS can be disconnected and you can still drive the truck. Maybe just in first gear. Is this true?

 

[subford]

So I have a question about the MLPS test. Do you test the pins on the actual switch, or do you test the connector that you pull off?

Yes just test it at the plug going to the E4OD.

 

[Skandocious]

I know what the manuals say but I was told as long as you do not use OD and manually shift the E4OD the MLPS can be disconnected and you can still drive the truck. Maybe just in first gear. Is this true?

I've honestly got no idea. I'm just going off what the manual says.

 

[NeXtras]

you sure its downshifting and not coming out of gear?

mine had an issue.. cleaned out the VSS and it rins fine now

 

[big tom]

Hey Gents, I wanted to update this thread. I changed the MLPS last weekend despite the snow and gravel dripping on my face (which was awful) but anyway I put about 500 miles on it this week w/ out a single hickup! So I am confident that it is fixed now. Thank you guys very much for the $50 fix.