ENGINE AR-PRIMARY 4253407 - Caterpillar

Neutral Position
Illustration 1 g03322440
Neutral position
(1) Magnetic screen (torque converter)
(2) Gear pump (transmission charge)
(3) Oil filter (power train)
(4) Bypass switch (oil filter)
(5) Temperature sensor (transmission oil)
(6) Modulating valve (transmission hydraulic control)
(7) Modulating valve (torque converter lockup clutch)
(8) Main relief valve
(9) Torque converter inlet relief valve
(10) Torque converter
(11) Temperature sensor (torque converter oil)
(12) Oil cooler (power train)
(13) Engine flywheel lubrication
(14) Transmission lubrication
(15) Speed sensor (transmission input)
(16) Speed sensor (transmission intermediate)
(17) Speed sensor 1 (transmission output)
(18) Speed sensor 2 (transmission output)
(19) Magnetic screen (transmission)
(20) Gear pump (scavenge)
(21) Transmission control
(22) Chassis ECM When transmission control (21) is moved to the NEUTRAL position, the position sensor on transmission control (21) sends a PWM signal to Chassis ECM (22). Chassis ECM (22) interprets the PWM signal as an operator request to move the transmission to NEUTRAL. Due to the NEUTRAL request, Chassis ECM (22) sends a signal to modulating valve (6) for the first clutch to engage. The signal activates the solenoid valve that moves a spool which redirects the oil in modulating valve (6). The oil is sent to the first clutch inside the planetary transmission. In neutral with only the first clutch engaged, neither directional clutch is energized.When the transmission is in the NEUTRAL position, oil is drawn from