Ford Explorer: Automatic Transmission - 10-Speed Automatic Transmission – 10R60 / Description and Operation - Transmission Description - System Operation and Component Description

System Diagram

System Operation

The 10R60 transmission is a 10-speed, step ratio rear wheel drive transmission that is controlled by a PCM. The 10R60 has ten forward speeds, one reverse speed, four planetary gearsets, one mechanical One-Way Clutch or OWC, six friction clutches, an upper valve body, a lower valve body with eight solenoids, and PCM controlled electronics. The 10R60 utilizes six shift (A-F) solenoids that are linear force solenoids. Unlike previous shift solenoids they are mechanical in nature in that no transmission fluid passes through them. CIDASs use a 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.

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 pedal 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 pedal 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 pedal, 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 downshifts 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 downshift.

Component Description

Hydraulic Circuits

Line Pressure Hydraulic Circuits

The PCM controls line pressure with the LPC solenoid. Varying pressure from the LPC solenoid affects shift feel while allowing sufficient pressure for clutch application.

When the engine is running, the pump supplies pressure to the main regulator valve through the pump output circuit. Pressure from the LPC solenoid through the LPC pressure circuit controls the position of the main regulator valve.

The main regulator valve varies pressure in the pump output circuit.

The transmission fluid auxiliary pump, an electronic pump in turned on before an engine stop event to maintain line pressure, allowing the transmission to stay engaged during the stop event. This allows quick response on the engine restart because the transmission is already in gear.

Lubrication Hydraulic Circuits

A small amount of hot fluid from the torque converter is routed through a small orifice in the separator plate to the transmission fluid cooler or transmission fluid warmer/cooler. This fluid purges the cooler or warmer/cooler of air and keeps the cooler or warmer/cooler full of fluid when the vehicle is running.

On vehicles without active warm up, most of the hot fluid from the torque converter is routed to the thermal bypass valve. When TFT is below a specified temperature, the thermal bypass valve directs the fluid to the lube circuit. When TFT is above a specified temperature, the thermal bypass valve directs fluid to the transmission fluid cooler. Cold fluid from the transmission fluid cooler is routed to the lube circuit.

On vehicles with active warm up, most of the hot fluid from the torque converter is routed through the bypass valve to the transmission fluid warmer/cooler. Cold fluid from the transmission fluid cooler is routed to the lube circuit.

Fluid in the lube circuit enters the input shaft through the front support assembly and flows through passages in the input shaft and output shaft to provide lubrication for the transmission.

Powerflows

1st Gear

The E clutch is applied allowing torque to be transferred from the input shaft to the shell and sun gear No. 4. The A clutch and the One-Way Clutch (OWC) are both applied to hold the ring gear No. 4 stationary on acceleration. The shell and sun gear No. 4 drives the pinions of the output shaft and planetary carrier No. 4 in a 4.69 reduction gear ratio. The D clutch is applied to reduce frictional losses from a released clutch, but does not contribute to powerflow.

2nd Gear

The One-Way Clutch (OWC) holds the sun gear No. 2 stationary on acceleration. The input shaft turns the planetary carrier No. 2 and causes the ring gear No. 2 and sun gear No. 3 to rotate at a 0.63 overdrive ratio. The C clutch and the D clutch are applied allowing torque to be transferred from the ring gear No. 2 to the planetary carrier No. 3 at a 0.63 overdrive gear ratio. The 2 inputs to the 3rd planetary gearset cause the ring gear No. 3 and the planetary carrier No. 3 to rotate at a 0.63 overdrive ratio. The A clutch and the One-Way Clutch (OWC) are both applied to hold the ring gear No. 4 stationary on acceleration. The shell and sun gear No. 4 drives the pinions of the output shaft and planetary carrier No. 4 in a 2.98 reduction gear ratio.

3rd Gear

The C clutch, D clutch, and the E clutch are applied to provide multiple inputs at the same speed to the 2nd and 3rd planetary gearsets. These inputs effectively lock the 2nd and 3rd planetary gearsets and cause sun gear No. 1 and the shell and sun gear No. 4 to rotate at a 1:1 ratio with the input shaft. The A clutch is holding the ring gear No. 1 stationary causing the planetary carrier No. 1 and the ring gear No. 4 to rotate at a 3.11 reduction ratio. The 2 inputs to the 4th planetary gearset cause the output shaft and planetary carrier No. 4 to rotate at a 2.15 ratio.

4th Gear

The C clutch, D clutch, and F clutch are applied effectively locking the 3rd and 4th planetary gearsets, the planetary carrier No. 1, and the ring gear No. 2 together. The A clutch is holding the ring gear No. 1. The 2 inputs to the planetary gearset No. 1 cause the sun gear No. 1 and the sun gear No. 2 to rotate at a 0.56 overdrive ratio. The input shaft turns the planetary carrier No. 2 and causes the ring gear No. 2 and the 4th planetary gearset to rotate at a 1.77 ratio.

5th Gear

The C clutch and F clutch are applied effectively locking the planetary carrier No. 1, the ring gear No. 2, and ring gear No. 4 together at a 1.77 ratio. The A clutch is holding the ring gear No. 1. The 2 inputs to the planetary gearset No. 1 cause the sun gear No. 1 and the sun gear No. 2 to rotate at a 0.56 overdrive ratio. The E clutch is applied to transfer torque to the sun gear No. 4. The 2 inputs to the 4th planetary gearset cause the output shaft and planetary carrier No. 4 to rotate at a 1.52 ratio.

6th Gear

The D clutch and F clutch are applied effectively locking the planetary carrier No. 1, the planetary carrier No. 3, and the ring gear No. 4 together. The A clutch is holding the ring gear No. 1. The 2 inputs to the planetary gearset No. 1 cause the sun gear No. 1 and the sun gear No. 2 to rotate at a 0.44 overdrive ratio. The input shaft turns the planetary carrier No. 2 and causes the ring gear No. 2 and sun gear No. 3 to rotate at a 3.58 ratio. The E clutch is applied to transfer torque from the input shaft to the ring gear No. 3 and the shell and sun gear No. 4. The 2 inputs to the 3rd planetary gearset cause the planetary carrier No. 3 and ring gear No. 4 to rotate at a 1.38 ratio. The 2 inputs to the 4th planetary gearset cause the output shaft and planetary carrier No. 4 to rotate at a 1.28 ratio.

7th Gear

The C clutch, D clutch, F clutch and the E clutch are applied to provide multiple inputs at the same speed to all four planetary gearsets. These inputs effectively lock all four planetary gearsets causing the output shaft and planetary carrier No. 4 to rotate at a 1:1 ratio with the input shaft.

8th Gear

The B clutch is holding the sun gear No. 2 stationary. The input shaft turns the planetary carrier No. 2 and causes the ring gear No. 2 and sun gear No. 3 to rotate at a 0.63 overdrive ratio. The D clutch and F clutch are applied allowing torque to be transferred from the planetary No. 3 to the ring gear No. 4 at a 0.82 overdrive gear ratio. The E clutch is applied allowing torque to be transferred from the input shaft to the shell and sun gear No. 4 at a 1:1 ratio. The 2 inputs to the 4th planetary gearset cause the output shaft and planetary carrier No. 4 to rotate at a 0.85 ratio.

9th Gear

The B clutch is holding the sun gear No. 2 stationary. The input shaft turns the planetary carrier No. 2 and causes the ring gear No. 2 to rotate. The C clutch and F clutch are applied allowing torque to be transferred from the ring gear No. 2 to the ring gear No. 4 at a 0.63 overdrive gear ratio. The E clutch is applied allowing torque to be transferred from the input shaft to the shell and sun gear No. 4 at 1:1 ratio. The 2 inputs to the 4th planetary gearset cause the output shaft and planetary carrier No. 4 to rotate at a 0.69 ratio.

10th Gear

The B clutch is holding the sun gear No. 2 stationary. The input shaft turns the planetary carrier No. 2 and causes the ring gear No. 2 and sun gear No. 3 to rotate. The C clutch, D clutch, and the F clutch are applied to provide torque input from the ring gear No. 2 at an overdrive ratio of 0.56. This torque input effectively locks the 3rd and 4th planetary gearsets causing the output shaft and planetary carrier No. 4 to rotate at a 0.64 ratio.

Reverse

The B clutch is applied to hold the sun gear No. 2 stationary. The input shaft turns the planetary carrier No. 2 and causes the ring gear No. 2 and the sun gear No. 3 to rotate at a 0.63 overdrive ratio. The A clutch, F clutch, and the D clutch are applied to hold the planetary carrier No. 3 stationary. The 2 inputs to the 3rd planetary gearset cause the ring gear No. 3 and the planetary carrier No. 4 to rotate at a 1.03 ratio in the reverse direction. The A clutch and F clutch are applied to hold the ring gear No. 4 stationary. The 2 inputs to the 4th planetary gearset cause the output shaft and planetary carrier No. 4 to rotate at a 4.85 reduction ratio in the reverse direction.

Component Description

Transmission Sensors

The PCM controls the electronic functions of this transmission. The PCM receives input signals from engine and transmission sensors and uses these inputs to control line pressure, shift time, TCC and shift solenoids.

Shift Solenoids

The 10R60 utilizes six shift (A-F) solenoids that are linear force solenoids. Unlike previous shift solenoids they are mechanical in nature in that no transmission fluid passes through them. CIDASs use a 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) has a corresponding shift solenoid (A-F) that is directly proportional in that zero current equals zero pressure and maximum current equals maximum pressure. Since there is no pressure with zero current if the power is interrupted to the shift solenoids none of the clutch packs are able to engage.

Torque Converter Clutch (TCC) Proportional (VFS) and Line Pressure Control (LPC) Solenoid (Inversely-Proportional (VFS)

Torque Converter Clutch (TCC) Proportional (VFS)

Normally Low Solenoid

The TCC solenoid is a variable force solenoid that varies hydraulic pressure by actuating a hydraulic valve. The TCC solenoid uses proportional operation. Normally low solenoids provide hydraulic pressure proportional to supplied current. A normally low solenoid will output very low pressure with low (50 mA) or no current, while it will supply high pressure with high current (850 mA).

Line Pressure Control (LPC) Solenoid (Inversely-Proportional (VFS)

Normally High Solenoid

The LPC solenoid is a variable force solenoid that varies hydraulic pressure by actuating a hydraulic valve. The LPC solenoid uses inversely proportional operation. Normally high solenoids provide full output of pressure with low or no current (50 mA) and very low pressure with high current (850 mA).

Transmission External Sealing

The front support cover and seal assembly has a bonded rubber seal around the outside that seals to the front support housing. A removable rubber seal on the inside of the front support cover seals the area around the front support cover bolt. A torque converter hub seal is held into the front support cover with a snap ring.

The front support assembly uses a large rubber seal that seals the support housing to the transmission case.

The transmission fluid cooler tubes use 2 rubber seals with plastic backing rings to seal the tubes to the transmission case.

On the left side of the transmission case, there is a line pressure tap plug.

The manual control shaft has a lip seal that is pressed into the transmission case.

The transmission fluid pan has a reusable gasket.

The output shaft uses a lip-type seal that seals to the transmission case and output shaft nut. The output shaft nut has a bonded rubber O-ring on the inside that seals to the shaft threads.

The large transmission case housing plug provides access to the park pawl shaft and has an O-ring seal.

The park pawl actuator sleeve has 2 O-ring seals that seal to the transmission case.

A plug seals the E clutch fluid passage in the rear of the transmission case.

The internal wiring harness bulkhead connector has 2 O-ring seals for the transmission case bore.

The transmission fluid level indicator plug uses an O-ring seal.

The transmission vent tube is pressed into the transmission case.

Vehicle Shift System

Park by Wire

• Uses a GSM with a rotary gear shift knob in place of a mechanical shifter for selecting P, R, N, D, M.
• The transmission hydraulic controls are modified using a park lock pawl valve connected to the park rod which unlocks and locks the park pawl from the carrier.
  • Uses clutch B and D hydraulic pressure to push the system out of Park.
  • Once out of Park, clutches A, B, C, D or F can continue to hold the system out of Park.
• A park lock pawl solenoid allows the system to remain out of Park when the engine is not running.
• The dual TR sensors indicate the state of the Park system and are not used to determine customer selected range, which is now provided by the GSM.
• A mechanical P override has been provided for in-plant use and towing. This consists of a cable running from the console to the transmission, a bracket and lever assembly mounted to the side of the transmission and a lever on the side of the transmission. In the override position the park lock pawl valve is held in the applied position to keep the park pawl unlocked from the carrier.

Drive Modes

The Selectable Drive Mode system customizes vehicle handling and performance for most driving conditions by utilizing sophisticated electronic vehicle systems. These systems optimize steering, handling and engine performance and transmission shifting to provide a robust driving experience. This provides a single location to control multiple systems performance settings.

Changing the drive mode automatically changes the functionality of the following systems:

• Electronically power-assisted steering system adjusts steering effort and feel based on the mode you select.
• Electronic stability control and traction control maintain your vehicle control in adverse conditions or high performance driving.
• Electronic throttle control enhances the powertrain response to your inputs.
• Driveline settings are optimized with shift schedules tuned to each drive mode.

The drive modes are ready to assist the driver in vehicle control for both on-road and off-road conditions. The modes are as follows:

On-Road Drive Modes

• Normal Mode: A perfect balance of excitement, comfort and convenience for everyday driving.
• Sport Mode: For aggressive on-road driving, sport mode increases throttle response, provides a sportier steering feel, along with quicker shifting. The transmission also holds gears longer, helping your vehicle accelerate faster when shifting gears.
• Tow Haul: For improved transmission operation when towing a trailer or a heavy load, tow haul mode moves upshifts to higher engine speeds to reduce the frequency of transmission shifting. This mode also provides engine braking in all forward gears, which slows the vehicle and assists in controlling the vehicle when descending a grade. The amount of downshift braking provided varies based on the amount the brake pedal is pressed.

Off-Road Drive Modes

• Snow/Wet (4X2) or Grass/ Gravel/Snow (AWD): For firm surfaces covered with loose or slippery material such as packed snow, ice, water, grass or a thin layer of gravel or sand.
• Sand Mode: For soft dry sand or deep gravel.
• Mud/Rut: For muddy, rutted, soft or uneven terrain.

For information on driving mode diagnosis,
Refer to: Four-Wheel Drive Systems - System Operation and Component Description (307-07A Four-Wheel Drive Systems, Description and Operation).