Fun With Transmissions - June - 2021

The New 10R140

In 2020, Ford motor company introduced the 10R140 ten speed automatic transmission for the Super Duty F-series trucks all the way up to the F-600. This unit will come behind the 6.2L 16V gas, 7.3L 2V gas and the 6.7L diesel engines. In this edition of Fun With Transmissions we’re going to introduce this unit to the transmission industry.

FORD’S DESCRIPTION

The 10R140 is a 10-speed, rear wheel drive transmission that’s controlled by a PCM for gas engine applications or a TCM for diesel engine applications. The 10R140 has ten forward speeds, one reverse speed, four planetary gear sets, one mechanical One-Way Clutch or OWC, six friction clutches, an upper valve body, a lower valve body with eight solenoids, and PCM or TCM controlled electronics. The 10R140 utilizes six shift (A-F) linear solenoids. Unlike previous shift solenoids they are mechanical in nature in that no transmission fluid passes through them. Casting integrated direct acting solenoids or CIDAS use an armature/pin assembly that moves a control valve in the main control valve body to control and apply hydraulic fluid pressure. Each clutch (A-F) is controlled by a corresponding shift solenoid (A-F). These solenoids are directly proportional in that zero current equals zero pressure and maximum current equals maximum pressure. If the power circuit to the transmission solenoids fails open, then all solenoids are failed electrically OFF, none of the clutch packs are able to engage and there is no fail-safe operation. This means when there is no power to the unit the transmission will be in neutral. Refer to the clutch apply chart (Figure 1) and the solenoid apply chart (Figure 2).

UPSHIFT GEAR SEQUENCE

At times the 10-speed transmission may skip gears when the vehicle starts from a complete stop. This is normal and desired behavior. At part throttle when acceleration is brisk, single step upshifts would result in very frequent shift events (very short time in gear). Double step upshifts results when a longer time is spent in gear. However, at light throttle or road load, single step upshifts will occur. The small 10-speed gear steps allow the engine speed to drop to lower values than it would in the 6-speed transmission; providing for the best fuel economy. In contrast, when the 10-speed transmission is at heavy or max throttle, the small steps keep the engine closer to the horsepower peak for best performance.

DOWN SHIFT GEAR SEQUENCE

At times the 10-speed transmission may skip gears when the vehicle down shifts to a complete stop. This is normal and desired behavior. The same skip shift strategy that is used for the upshift may be applied during down shift.

DRIVE MODES

Optimum shift quality is provided in Drive (D) when the Normal Drive Mode is selected. In Manual (M) or when a different Drive Mode is selected, the strategy will provide more aggressive shifts at higher engine speeds. This is normal and desired behavior.

THE TORQUE CONVERTER

This unit is big! The torque converter alone weighs in at a stout 71lbs! (Figure 3). Another large feature on the torque converter is the hub (figure 4). The hub diameter is just north of 3 inches across.

Because the torque converter is so heavy the factory recommends removing and installing with a crane. I know some of the younger generation might think this is extreme and that sliding the converter in by hand is easy. Well folks I am here to tell you those days are long gone for us older guys. Its ok to use a universal pump puller as a holding fixture and a bit of chain and a cherry-picker for the job (figure 5).

PLANETARY GEAR SETS

The planets in this unit, just like the torque converter, are big and built for horsepower and torque. Ford states that this unit is rated to 475 hp and a whopping 1,050 ft-lbs of torque. This unit also has an impressive gear ratio spread from 4.61:1 in 1st gear to 0.63:1 10th gear. It can be noted that 8th, 9th and 10th gear are all overdrive ratios (figure 6).

Remember, the Lepelletier (pronounced: La-pelt-e-ay) geartrain that’s in the 6R80 and the 6L90? The basic principle is that when a simple planetary gear set has two inputs it creates another gear ratio. This gear ratio will be different than a simple planet having only one input.

To simplify: if the sun gear is the input, the planet will have a certain ratio. If the sun gear and the ring gear are both inputs, the planet will have a completely different ratio. The 10R140 uses 1 and 2 inputs to all four of the planets in the unit to achieve 10 forward speeds.

TRANSMISSION FLUID COOLING SYSTEM

The 10R140 transmission cooling system is slightly different than what we are seeing these days. Most of the ford products right now are using a thermal bypass valve either in the valve body or in the pump. These valves help speed up the temperature of the transmission fluid, then it stays open to maintain fluid temperature in the cooling system.

The 10R140 transmission fluid cooling system uses a coolant control valve attached to the coolant return hose which restricts coolant flow through the warmer when the transmission fluid is cold. This will warm the fluid faster. At a predetermined temperature, the PCM signals the valve to open, allowing coolant flow to the warmer. This will cool the warm fluid (figure 7).

ADAPTIVE LEARNING DRIVE CYCLE

The Adaptive Learning Drive Cycle must be performed after any of the following procedures are performed:

  • Transmission rebuild or replaced
  • TCM replaced or reprogrammed
  • Major engine work performed
  • Air/fuel management adaptive values reset

Perform the adaptive learning drive cycle on a level road surface.

  1. Using the scan tool, clear the DTCs (Diagnostic Trouble Codes) and Transmission Adaptive Tables.
  2. Drive the vehicle until the engine and transmission reach normal operating temperature.
  3. Accelerate from a stop with light throttle (15%) ensuring that upshifts 1st through 8th occur at engine speeds between 1300-1600 rpm.
  4. Continue to accelerate (may apply slightly more throttle after 7-8 upshift at 32-38 mph (51-61 km/h) until you achieve 55 mph (88 km/h) and the 8-9 and 9-10 shifts complete.
  5. Brake very gently to a complete stop and hold foot on brake for five (5) seconds.
  6. Shift the transmission to Neutral. Wait 1 second.
  7. Shift the transmission to Reverse. Wait 2 seconds.
  8. Shift the transmission to Neutral. Wait 1 second.
  9. Shift the transmission to Drive. Wait 2 seconds.
  10. Repeat Steps 3 through 9 six additional times.

This new heavy duty 10 speed is a monster to handle the big trucks with the big horse power and big torque numbers. In future Fun With Transmissions articles we will compare this beast to the competition out there. Until then keep having Fun with Transmissions!