Ford 4R100 Automatic Transmission

4R100 Transmission Specs & Ratios

The 4R100 four speed automatic transmission was introduced to Ford's portfolio beginning the 1999 model year. It is an improvement of the E4OD, and although they share no components their platforms are somewhat similar. The 4R100 is the last derivative of the venerable C6 and carried its legacy in the departments of durability. The transmission is rated with a nominal 1000 ft-lb maximum input torque capacity, although the figure is rather misleading and does not correspond to the maximum rated engine torque.

The 4R100 was largely introduced because of Ford's need for a heavy duty transmission that could handle the torque output of the evolving 7.3L Power Stroke. Because of the transmission's relatively high capacity, it found its way into the 5.4L Supercharged F-150 Lightning and Harley Edition models. The 5R110W TorqShift transmission would eventually replace the 4R100 in the Super Duty, while the 4R70W and 4R75W transmissions would dominate the F-150 platform until the 6R80 was introduced for 2009.


Ford 4R100 Transmission Gear Ratios






2.71 : 1

1.54 : 1

1.00 : 1

0.71 : 1

2.18 : 1


Ford 4R100 Transmission Specs


Ford 4R100


4 speed overdrive automatic transmission


Ford E4OD


1999 - 2004 Ford F-150 Lightning
1999 - 2003 Ford Super Duty
2002 - 2003 Ford F-150 Harley Edition
1999 - 2003 Ford Expedition
2000 - 2003 Ford Excursion

Case Material:


Max Input Torque:

1000 lb-ft (nominal transmission input torque capacity)


Approximately 270 lbs

ATF Type/Spec:

17-18 quarts maximum capacity, MERCON V ATF (original fluid spec was the now defunct MERCON ATF)

Service Intervals:

Replace transmission fluid and filter every 30,000 miles


• Based on the E4OD platform, a derivative of the original C6, but with no interchangeable parts

• Four element torque converter

• 3 planetary gear sets (one for reverse, forward gears, and overdrive)

• Power take-off (PTO) provisions available on select transmissions in applications with a GVWR greater than 8,500 lbs (various Ford Super Duty)

• Parts between gas and diesel, F-150 and Super Duty applications may not be interchangeable


Four forward gears


Rear wheel drive applications


1000 lb-ft nominal max input torque capacity


4R100 Line Pressure Test Procedures

Selected Gear

Pressure Spec @ Idle

Pressure Spec @ Stall Speed

Park (P)

50 - 65 psi


Neutral (N)

50 - 65 psi


Reverse (R)

70 - 100 psi

220 - 240 psi

Drive (D)

50 - 65 psi

136 - 156 psi

Manual 2 (2)

50 - 65 psi

136 - 156 psi

Manual 1 (1)

7 - 115 psi

175 - 210 psi

Pressure specs are NOT application specific and are applicable to all 4R100 transmissions

Checking the line pressure on the 4R100 requires installing a transmission pressure gauge (minimum 300 psi) at the line pressure port. The line pressure port is located on the driver side of the transmission just above the lip of the transmission fluid pan and roughly centered between the transmission input and output.

The idle pressure test should always precede the stall speed pressure test. If the transmission fails the idle pressure test, do not perform the stall speed test - not only can severe transmission damage ensue, but there is no need to perform the test if any of the selected ranges fail the idle test.

The stall speed test requires briefly depressing the accelerator pedal to the full throttle position. Once the engine speed (RPM) reaches an equilibrium state and is no longer increasing (indicating stall speed has been achieved), read the pressure and release the accelerator pedal. When performing the test, do NOT hold the accelerator pedal for more than a few seconds - severe transmission damage may occur. This test places tremendous strain on the transmission and therefore is highly time sensitive.

Compare the results of the pressure test to the Ford spec from the chart above. If any range does not fall within spec, repairs are necessary. During the test, use common sense safety practices and redundant measures (chocking all wheels and setting the parking brake for the stall speed test, for example) to reduce the risk of personal injury and/or vehicle damage.