E40D issues
Thread Starter
|
6th Gear
Joined: Apr 2026
Posts: 6
Likes: 0
E40D issues
I have a 1997 f250 7.3PS e40d 4x4. I have lost overdrive while driving highways speeds and significantly harder shifts in the remaining 3 gears almost as if line pressure was raised. At the same time this has happened I can hear a distinct whining noise coming from specifically the bell housing/torque converter area that becomes louder as rpms go up. also od/off light flashing. I am wondering if these transmissions have a limp mode and if the fault is in the torque converter and that is what has caused the loss of overdrive and higher line pressure feel? looking for diagnostic help and where to start. thanks.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,695
Likes: 2,616
From: SE Florida
The torque converter can't affect overdrive.
The ONLY way to fix this is to read the codes. Then we can help direct you to the problem. Anything else is just guessing, and will waste a lot of time and money.
The ONLY way to fix this is to read the codes. Then we can help direct you to the problem. Anything else is just guessing, and will waste a lot of time and money.
Thread Starter
|
6th Gear
Joined: Apr 2026
Posts: 6
Likes: 0
After finding that code I decided to clear it and try and reproduce the issue. I started driving it with codes cleared and it felt like it was back to normal again. no hard shifts, almost as if a "limp mode" was removed. everything seemed normal until it would shift into 3rd gear and i could feel it trying to engage converter lockup and it kept slipping and wouldn't lock. any thoughts?
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,695
Likes: 2,616
From: SE Florida
Clearing the code does remove the FMEM (Failure Mode Effects Management) aka, limp mode.
You most likely have a failure in the torque converter lockup system. Since you don't have an electrical code, we can rule out the PCM, wiring, and the solenoid. It could be a bad seal on the input shaft, a bad converter, or a stuck converter clutch control valve. The trans needs to come out to check each of these.
You most likely have a failure in the torque converter lockup system. Since you don't have an electrical code, we can rule out the PCM, wiring, and the solenoid. It could be a bad seal on the input shaft, a bad converter, or a stuck converter clutch control valve. The trans needs to come out to check each of these.
Thread Starter
|
6th Gear
Joined: Apr 2026
Posts: 6
Likes: 0
okay thank you. Are you saying that the p1728 code is not an electrical code? what does this code mean? on the scan tool I was using it just said something along the lines of "transmission slippage" and nothing to do with torque converter.
thanks
thanks
Trending Topics
Thread Starter
|
6th Gear
Joined: Apr 2026
Posts: 6
Likes: 0
I forgot to mention that after I cleared the codes, the whining noise coming from the torque converter/bell housing area had went away. That confused me a bit.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,695
Likes: 2,616
From: SE Florida
The noise is from the pump. When certain codes are set, and P1728 is one of them, the transmission defaults to high line pressure. That can cause noise from the pump.
Thread Starter
|
6th Gear
Joined: Apr 2026
Posts: 6
Likes: 0
Thank you for that information. knowing all of this, when I go to put everything back together are there any upgrades or improvements I should be making to the transmission specifically on the torque converter circuit side of things to keep this from happening again? maybe increasing line pressure? Also, say I wanted to replace the factory torque converter with a triple disc converter, does this require any tuning or other upgrades?
Lead Driver
Joined: Apr 2016
Posts: 7,170
Likes: 1,331
From: Bahstun
triple disc is just the TC clutch like plates inside and OEM uses a single that can only hold maybe 300 HP according to interwebs
The stall speed on OEM is a bit high which creates more heat and the cooling system is oversized for this, the lower stall ones apply power at lower RPMs and reduce heat
There are seals, bearing and pump circuit mods that can be done.
The stall speed on OEM is a bit high which creates more heat and the cooling system is oversized for this, the lower stall ones apply power at lower RPMs and reduce heat
There are seals, bearing and pump circuit mods that can be done.
Fleet Owner
Joined: Jul 2006
Posts: 20,322
Likes: 789
From: Mi'kma'ki
Thank you for that information. knowing all of this, when I go to put everything back together are there any upgrades or improvements I should be making to the transmission specifically on the torque converter circuit side of things to keep this from happening again? maybe increasing line pressure? Also, say I wanted to replace the factory torque converter with a triple disc converter, does this require any tuning or other upgrades?
The Installation Of Transgo's 'Tugger' Reprogramming Kit (Shift Kit For HD Hauling & Towing)
Thread
Thread Starter
Forum
Replies
Last Post
muddy84f250
1994.5 - 1997 7.3L Power Stroke Diesel
9
Sep 2, 2013 08:26 PM
coreyallan01
Clutch, Transmission, Differential, Axle & Transfer Case
5
Jun 4, 2013 09:29 PM
Ultraute
Clutch, Transmission, Differential, Axle & Transfer Case
2
Feb 13, 2005 10:18 AM