Leaking E40D
Thread Starter
|
Freshman User
Joined: Feb 2007
Posts: 44
Likes: 0
From: Ozark, MO
Leaking E40D
My girl friend has a '91 F-150 with the 300 straight six and E40D and it is leaking transmission fluid from a rubber plug in the bottom of the bell housing when it is warm and running. What is the name of this part, and is this an indication of another problem?
Transmission Rebuilder
Joined: Jul 2008
Posts: 1,569
Likes: 62
From: North Georgia
That is a inspection hole, that plug just keeps dirt out of the bell housing.
Your transmission is leaking out the front area of the trans, could be front seal or pump o-ring or the pump bushing spun, or a cracked converter.
Your transmission is leaking out the front area of the trans, could be front seal or pump o-ring or the pump bushing spun, or a cracked converter.
Lead Driver
Joined: Aug 2006
Posts: 5,670
Likes: 12
From: Sand Lake, MI
Has to be, the plug is just in a hole in the bell housing itself, It holds no fluid.
Elder User
Joined: Apr 2007
Posts: 617
Likes: 0
From: Los Alamos
All the possible leak points he mentioned are up in the bell housing area..thats where it will come from..
Lead Driver
Joined: Feb 2002
Posts: 7,952
Likes: 589
From: Greater Austin, Texas
Most likely the converter seal is bad. This is typically caused by heat buildup due to another problem, usually the lockup clutch in the converter has failed. Do you know if your converter clutch is working or not?
Thread Starter
|
Freshman User
Joined: Feb 2007
Posts: 44
Likes: 0
From: Ozark, MO
It seems to shift fine, it is a little rough on the 1-2 shift but that seemed normal to me, what is the sign of the convertor clutch not working? If I drop the pan and do a filter and new fluid swap would that ease the situation.
Trending Topics
Lead Driver
Joined: Feb 2002
Posts: 7,952
Likes: 589
From: Greater Austin, Texas
Run the truck at a steady 50mph, and while holding this speed, tap the brake pedal. The RPM on the tach should go up briefly and then return to where it was. If it doesn't change, your converter clutch is not engaging.
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
Thread Starter
|
Freshman User
Joined: Feb 2007
Posts: 44
Likes: 0
From: Ozark, MO
I took the truck for a drive on the highway, when you let off the gas and touch the brake the RPM just drops with the speed, but when you pick up on the throttle again the rpm raises slightly and the torque covertor re-engages normally. The leak has seemed to slow to a small drip.
Lead Driver
Joined: Aug 2006
Posts: 5,670
Likes: 12
From: Sand Lake, MI
The tranny is likely overheating, if so replacing the seal won't help.
Check the cooling system for it, make sure the cooler is in good shape and the lines are not kinked or pinched. Make sure the cooling fan's clutch locks up as it should.
Also make sure the fluid cooler is mounted with very little gap between it and the radiator. If someone replaced the stock cooler with a after market cooler they tend to mount them to far forward. No air is drawn through em by the cooling fan like that. A fan shroud is needed as well, if its gone, put one back on it.
A sure sign it's the problem is the tranny leaks when in stop and go traffic sitting at traffic lights but stops when you break out onto the open road and it quits leaking. The steady air flow brings its temp down stopping the over pressure creating the leak.
Check the cooling system for it, make sure the cooler is in good shape and the lines are not kinked or pinched. Make sure the cooling fan's clutch locks up as it should.
Also make sure the fluid cooler is mounted with very little gap between it and the radiator. If someone replaced the stock cooler with a after market cooler they tend to mount them to far forward. No air is drawn through em by the cooling fan like that. A fan shroud is needed as well, if its gone, put one back on it.
A sure sign it's the problem is the tranny leaks when in stop and go traffic sitting at traffic lights but stops when you break out onto the open road and it quits leaking. The steady air flow brings its temp down stopping the over pressure creating the leak.
More Turbo
Joined: Mar 2008
Posts: 658
Likes: 2
If its leaking 'pretty damn bad' from just stop and go traffic, you will most likely need to replace the seal anyways. The seal itsself is interesting, it has a metal outer ring that sits in the tranny, and the inner portion has a little rubber flap that encircles the converter shaft. This flap is held tight with a spring. When the fluid gets too hot, the spring stretches, and fluid goes everywhere. As aforementioned, check that the fan clutch is functioning. To check for proper fluid flow, unscrew the cooler line that flows from the trans to the cooler, at the cooler(hot side) and run the engine. Fluid should come out at the rate of about 1 quart per 30 sec. If it does not, you pump is broken, or the line is plugged. If flow is ok, preform the same test on the line returning from the cooler to trans (cool side) at the transmission - this will tell you if the cooler is plugged. If everything checks out then the converter may be burning up. Anyways, let us know that you find out...
Lead Driver
Joined: Feb 2002
Posts: 7,952
Likes: 589
From: Greater Austin, Texas
I took the truck for a drive on the highway, when you let off the gas and touch the brake the RPM just drops with the speed, but when you pick up on the throttle again the rpm raises slightly and the torque covertor re-engages normally. The leak has seemed to slow to a small drip.
Post Fiend
Joined: Mar 2002
Posts: 19,402
Likes: 38
From: Bonita Springs FL
His description sounds like the converter is locking up fine. That's exactly what mine does.