92 F350 7.3idi E4OD limp mode?

[backyard_mechanic]

Be mindful this is my first post in a forum of this sort ever

I bought my 92 7.3 E4OD pickup with 314k and was told the trans was replaced. Transmission shifted harder then normal but I was also told it had a shift kit. I lost overdrive about 4k miles down the road and a friend informed me there are a number of things that can cause it to be in “limp mode”

My truck has been missing the gear shift handle and overdrive switch since before I owned it. Can that cause the trans to be in limp mode?

I’m going to plug a code reader into it this week but I wanted to start a thread on my specific issue to see if I can get some guidance.

Much appreciated!

 

[ISPKI]

The truck is missing the column shift lever? How do you put it in and out of gear? The O/D button is wired into the handle so you would have to figure out how that circuit was wired to compensate for the missing lever.

When you say it lost overdrive, is it just not shifting into OD or is it only shifting up a couple gears and not making it to 4th? If the truck is in Limp Mode it will only shift up to 2nd or 3rd gear and you wont be able to get over 30ish mph. Also - It will shift violently, almost feels like someone is rear ending you every single time it shifts.

If the truck's O/D is just disabled due to missing the stalk, then it should drive OK but it wont be able to get that last shift in at higher speeds.

 

[backyard_mechanic]

The truck is missing the column shift lever? How do you put it in and out of gear? The O/D button is wired into the handle so you would have to figure out how that circuit was wired to compensate for the missing lever.

When you say it lost overdrive, is it just not shifting into OD or is it only shifting up a couple gears and not making it to 4th? If the truck is in Limp Mode it will only shift up to 2nd or 3rd gear and you wont be able to get over 30ish mph. Also - It will shift violently, almost feels like someone is rear ending you every single time it shifts.

If the truck's O/D is just disabled due to missing the stalk, then it should drive OK but it wont be able to get that last shift in at higher speeds.

I bought the truck for $1500 and the previous owner broke the shift tube along with the lever. I ended up just fastening the cable to the column and I just pull
the cable into whatever gear (I’ve gotten pretty good at it) the truck would shift hard but it would go into overdrive. I lost overdrive going about 65 pulling a hill. Truck downshifted then on flat ground wouldn’t up shift again until a few minutes later. Was still able to do 60 in 3rd. It did that a couple more times until overdrive was non existent. Found quite a bit of metal on the pan and I’m sure it’s going to need a tranny soon but I’d like to figure out limp mode before I put a trans in it not after

 

[ISPKI]

So you dropped the Transmission oil pan and found chunks of metal in the bottom of it? Lots of microscopic shavings clumped around the magnet is not uncommon, especially since people tend not to clean them out...ever, it seems.

Hows the fluid? Did you change the filter when you had the pan off? Limp mode can be caused by bad sensor signals from the VSS (rear axle) the FIPL (Side of the IP) and the tach sensor (Chunky hex shaped plug next to the IP gear cover). All of those sensors wear out and fail after some time. VSS is supposed to be changed every 50kish, guess how often that actually happens?

The FIPL on the side of the IP has a wide range of adjustment and if it is off enough it can cause limp mode. They arent expensive parts are wear out over the course of around 40k miles. My truck used to slip into limp mode from time to time. Tell tale sign that it may be the FIPL is if it is swung to the max on one end of it's adjustment. Usually worth while installing a new one for about 35$. Need a multi meter to adjust it in.

After the FIPL, I changed the filter in the Trans and flushed the whole system several times with Wolf synthetic trans fluid. Also replaced the VSS cuz those are cheap. My speedo and tach seemed fine so I left the Tach sensor alone. Baddabing, no more limp mode, trans shifts crisp and strong and has been great for about a year and a half of wood hauling.

 

[backyard_mechanic]

This is what the pan looked like. I did a full trans flush and service 4k miles ago. Picking up a code reader today and going to pull the codes. If I can get it shifting thru all the gears on jack stands with no load I’ll be happy to put a new transmission in it. But I don’t want to blow another one. Thanks for the info it gives me a good starting point.

 

[ISPKI]

The shavings on the magnet dont look terrible, mine looked like a shrew growing on the thing. The fragments in the bottom of the pan is concerning. These transmissions are self contained systems, aside from the few sensor signals, nothing else really interacts with them. I would check the FIPL voltage and replace if necessary. Take a look at this thread, should give you the info you need.

https://www.oilburners.net/threads/fipl-sensor.64436/

 

[backyard_mechanic]

So you dropped the Transmission oil pan and found chunks of metal in the bottom of it? Lots of microscopic shavings clumped around the magnet is not uncommon, especially since people tend not to clean them out...ever, it seems.

Hows the fluid? Did you change the filter when you had the pan off? Limp mode can be caused by bad sensor signals from the VSS (rear axle) the FIPL (Side of the IP) and the tach sensor (Chunky hex shaped plug next to the IP gear cover). All of those sensors wear out and fail after some time. VSS is supposed to be changed every 50kish, guess how often that actually happens?

The FIPL on the side of the IP has a wide range of adjustment and if it is off enough it can cause limp mode. They arent expensive parts are wear out over the course of around 40k miles. My truck used to slip into limp mode from time to time. Tell tale sign that it may be the FIPL is if it is swung to the max on one end of it's adjustment. Usually worth while installing a new one for about 35$. Need a multi meter to adjust it in.

After the FIPL, I changed the filter in the Trans and flushed the whole system several times with Wolf synthetic trans fluid. Also replaced the VSS cuz those are cheap. My speedo and tach seemed fine so I left the Tach sensor alone. Baddabing, no more limp mode, trans shifts crisp and strong and has been great for about a year and a half of wood hauling.

Greatly Appreciate the help. I'll report back on what I find.

 

[backyard_mechanic]

So you dropped the Transmission oil pan and found chunks of metal in the bottom of it? Lots of microscopic shavings clumped around the magnet is not uncommon, especially since people tend not to clean them out...ever, it seems.

Hows the fluid? Did you change the filter when you had the pan off? Limp mode can be caused by bad sensor signals from the VSS (rear axle) the FIPL (Side of the IP) and the tach sensor (Chunky hex shaped plug next to the IP gear cover). All of those sensors wear out and fail after some time. VSS is supposed to be changed every 50kish, guess how often that actually happens?

The FIPL on the side of the IP has a wide range of adjustment and if it is off enough it can cause limp mode. They arent expensive parts are wear out over the course of around 40k miles. My truck used to slip into limp mode from time to time. Tell tale sign that it may be the FIPL is if it is swung to the max on one end of it's adjustment. Usually worth while installing a new one for about 35$. Need a multi meter to adjust it in.

After the FIPL, I changed the filter in the Trans and flushed the whole system several times with Wolf synthetic trans fluid. Also replaced the VSS cuz those are cheap. My speedo and tach seemed fine so I left the Tach sensor alone. Baddabing, no more limp mode, trans shifts crisp and strong and has been great for about a year and a half of wood hauling.

Just pulled codes Looks like code 23 for the FIPL and code 62 is converter clutch error.

 

[ISPKI]

Just pulled codes Looks like code 23 for the FIPL and code 62 is converter clutch error.

Did you do the test with the truck off? I dont recall exactly but I believe if you test it with the truck off and not in gear or something silly, it will always return a code 62, OR that code 62 is stored in the memory so if the clutch ever slipped it will show up until you clear the codes.

I would start by looking at the FIPL values and adjust that into range first and foremost. At the same time I would suggest trying to source a shifter stalk with the O/D switch on it. I may have one that I could salvage off a parts truck.

 

[backyard_mechanic]

Did you do the test with the truck off? I dont recall exactly but I believe if you test it with the truck off and not in gear or something silly, it will always return a code 62, OR that code 62 is stored in the memory so if the clutch ever slipped it will show up until you clear the codes.

I would start by looking at the FIPL values and adjust that into range first and foremost. At the same time I would suggest trying to source a shifter stalk with the O/D switch on it. I may have one that I could salvage off a parts truck.

I tested Key on engine off. I have the original shifter stalk but I ended up just wiring the harness so I could have a button on the dash for overdrive. Going to test the FIPl values today and see what I find. Also going to inspect the harness and connectors

 

[backyard_mechanic]

Did you do the test with the truck off? I dont recall exactly but I believe if you test it with the truck off and not in gear or something silly, it will always return a code 62, OR that code 62 is stored in the memory so if the clutch ever slipped it will show up until you clear the codes.

I would start by looking at the FIPL values and adjust that into range first and foremost. At the same time I would suggest trying to source a shifter stalk with the O/D switch on it. I may have one that I could salvage off a parts truck.

Tested 1.2 at idle and 3.9 wot. Voltage increases pretty smooth. Guessing I just need to adjust is properly. But probably won’t fix my missing od

 

[ISPKI]

So its a little low I think. Yeah try adjusting it up and clear your codes then see if anything changes. Based on the earlier image you posted of the fluid and fragments, you might need to flush the fluid again also. Still concerning where the debris came from.

 

[backyard_mechanic]

So its a little low I think. Yeah try adjusting it up and clear your codes then see if anything changes. Based on the earlier image you posted of the fluid and fragments, you might need to flush the fluid again also. Still concerning where the debris came from.

I thought spec was .9v to 4v

 

[ISPKI]

Good question...I dont recall and there was an update released at some point to update the spec. Quick google search showed .8-1.2 at idle and 4.0-4.4 at WOT. So youre at the high end on the idle and low on the WOT values. I suppose, if your truck idles a little higher than expected or if your throttle linkage is worn (im guessing they all are) then the idle value could be skewed, either way I would try adjusting it a bit.

 

[ISPKI]

Looks like 1.1 at Idle and 3.8-4.3 at WOT is supposed to be ideal.