Manual LOW Position and 1st Gear Below 5 km/h (3 mph)

Mechanical Operation -   Apply components:

• Forward (1, 2, 3, 4) clutch
• Low/reverse clutch
• Low one-way clutch

Planetary Gearset Operation -   Front planetary gearset driven components:

• Ring gear
• Planetary carrier

Center planetary gearset driven components:

• Sun gear
• Planetary carrier

Rear planetary gearset driven components:

• None

Front planetary gearset held components:

• Sun gear

Center planetary gearset held components:

• Ring gear

Rear planetary gearset held components:

• Rear planetary carrier (does not contribute to power flow)

For component information, refer to Mechanical Components and Functions .

Fig 1: Power Flow

Courtesy of FORD MOTOR CO.

Hydraulic Operation -   Line pressure hydraulic circuits:

• Line pressure from the pump is supplied to the manual valve.
• Line pressure is regulated by the pressure regulator valve.
• The pressure regulator valve is controlled by varying pressure from the LPC solenoid through the LPC circuit.

Torque converter circuits:

• Regulated line pressure from the pressure regulator valve is directed to the TCC control valve through the CONV FD hydraulic circuit.
• When the TCC is released, CONV FD pressure is directed to the TCC RELEASE circuit by the TCC control valve. Pressure from the TCC RELEASE circuit releases the TCC.
• Transmission fluid from the TCC RELEASE returns to the TCC control valve through the TCC APPLY circuit.

Cooler and lubrication hydraulic circuits:

• The TCC control valve directs transmission fluid from the TCC APPLY circuit (return circuit from the torque converter when the TCC is released) to the COOLER FEED circuit.
• In the COOLER FEED circuit, transmission fluid flows through the transmission fluid cooler or the thermal bypass valve to the LUBE circuit.

Solenoid hydraulic circuits:

• The LPC solenoid applies varying pressure to the pressure control valve through the LPC hydraulic circuit. The LPC solenoid regulates line pressure by controlling the position of the pressure regulator valve.
• SSA applies pressure to the forward (1, 2, 3, 4) clutch regulator valve to apply the forward clutch.
• SSD applies pressure to the low/reverse/overdrive (4, 5, 6) regulator valve to apply the low/reverse clutch.
• SSE applies pressure to the multiplex shift valve to position the valve against the spring and direct regulated CBLR/C456 SUPPLY pressure to the low/reverse clutch.

Clutch hydraulic circuits:

• Line pressure from the manual valve is directed to the multiplex shift valve through the DRIVE 1 hydraulic circuit.
• The multiplex shift valve directs DRIVE 1 pressure to the multiplex manual valve through the REV DRIVE B circuit.
• The multiplex manual valve directs REV DRIVE B pressure to the DRIVE 2/DRIVE B shuttle ball where it enters the CB26FD/CB1234FD circuit.
• The CB26FD/CB1234FD circuit feeds the forward (1, 2, 3, 4) clutch through the CB1234 SUP circuit.
• Regulated DRIVE 2 pressure from the forward (1, 2, 3, 4) clutch regulator valve is directed to the forward (1, 2, 3, 4) clutch through the CB1234 hydraulic circuit to apply the clutch.
• Regulated line pressure from the low/reverse/overdrive (4, 5, 6) regulator valve is sent to the multiplex shift valve assembly through the CBLR/C456 SUPPLY hydraulic circuit.
• The multiplex shift valve directs the transmission fluid to the low/reverse clutch through the CBLR hydraulic circuit.

For additional hydraulic circuit and information, refer to Hydraulic Circuits .

Electrical Operation -   Solenoid operation:

Fig 2: Identifying 6F50 Manual LOW Position and 1st Gear Below 5 km/h (3 mph) Position Pressure Circuits

Courtesy of FORD MOTOR CO.