SHIM (1.8 MM THICK) 6T8643 - Caterpillar

Illustration 1 g01092689
Location of the Transmission Clutch Solenoid Modulating Valve
(1) Number 1 clutch solenoid modulating valve (Reverse)
(2) Number 2 clutch solenoid modulating valve (Forward)
(3) Number 3 clutch solenoid modulating valve (Fourth Speed)
(4) Number 4 clutch solenoid modulating valve (Third Speed)
(5) Number 5 clutch solenoid modulating valve (Second Speed)
(6) Number 6 clutch solenoid modulating valve (First Speed)
Illustration 2 g00562502
Transmission Clutch Solenoid Modulating Valve
The six clutch solenoid modulating valves are mounted on the top of the transmission under the cab. There is one clutch solenoid modulating valve for each of the six transmission clutches.The clutch solenoid modulating valves are outputs of the power train electronic control module (ECM). The clutch solenoid modulating valves are proportional solenoid valves. The clutch solenoid modulating valves are used by the power train ECM to directly modulate the oil pressure that is sent to each individual clutch. When the operator selects a direction or when the operator selects a speed the power train ECM sends a pulse width modulated signal (PWM) in order to vary the current to the clutch solenoid. The distance that is travelled by the solenoid plunger (valve) is proportional to the electrical current of the solenoid. The position of the solenoid plunger (valve) controls the oil pressure of the selected clutch. The amount of current that is sent to the clutch solenoid modulating valve regulates the amount of oil pressure that is supplied to the selected clutch. When the power train ECM sends the maximum current to the clutch solenoid modulating valve, the oil pressure in the clutch is at the maximum. When no current is sent to the clutch solenoid modulating valve, the oil pressure in the clutch should be zero.The power train ECM will activate the transmission clutch solenoid modulating valve that is selected by the operator. Clutch solenoid modulating valves (1) and (2) supply oil to the direction clutches. Clutch solenoid modulating valves (3), (4), (5) and (6) supply oil to the speed clutches. In order