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Automatic Transmissions

Ford E40D / 4R100 “Bad Boy” Description 


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The E40D was Ford's answer to the demand for a heavy duty, C6 level automatic overdrive transmission. In 1998 this trasnmission was replaced by the 4R100. While these transmissions seem to survive fairly well in trucks where the truck is used for general duty transportation, when the transmission is used for heavy towing, high load, motorhome , or extreme off road use, is has developed a reputation as failure prone. 

First, we feel that Ford engineers were directed by marketing types to make  the trans shift more like a luxury car and lee like a truck.  Apparently, the larger segment of truck owners wanted a soft ride to a real truck that shifts like a truck, etc. These "niceties" involve compromises that make a pretty good basic trans design unable to hold up under real truck use. 

One answer many truck owners have resorted to in conversion to a manual trans. We have found conversion to an NV4500 to be a popular solution.

“Bad Boy” is a designation  High Impact adds to it's custom built line of aftermarket  automatic transmissions to differentiate it from a stock replacement transmission. These E4OD transmissions are built for aftermarket conversions and applications where the demands placed upon the transmission far exceed anything Ford ever built the E4OD for.

There a number of standard upgrades included in all Bad boy units, such as an upgraded HD torque converter with furnace brazed turbine elements and HD lock up clutches, oversize sprags, upgraded pressure regulator and reverse boost valve, and internal modifications for improved oiling and shifting.  All "BadBoy" e40D transmissions include upgrade to a ball bearing center support

A Bad Boy is typically engineered and built for a specific application. Diesel applications require further pump upgrades. Racing applications require ability to handle hard shifts high RPMs as a matter of course. 4WD applications must operate reliably at crazy angles, and not slip, even at very low crawling RPMs. Towing applications must be able to withstand sustained high torque. 4WD and Towing both tend to exaggerate the heat loads. Shift firmness and shift points are calibrated to the application.  

Electronic Control

The E4OD requires a computer for shift control. The Factory ford programming, we feel, is one of the primary culprits preventing the E4OD reach its full potential. E4OD "Bad Boy" systems incorporate an external, fully user programmable stand-alone computer. This computer allows the transmission programming to be optimized for durability and to shift as the application requires. It can be used in conjunction with the Ford computer, in computer controlled engine applications, or it may be used entirely stand-alone, in vehicles the do not have any engine computer controls.

We base our Ford systems on one of two controllers:

Bauman Engineering "Baumanator" TCM 

Powertrain Control Solutions TCM


Main Case 27-3/4" long

Standard OEM 4WD adapter casting 4-5/8" long


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