PLENUM 2634796 - Caterpillar

631K
Illustration 1 g06228771
(1) Accelerator pedal
(2) Transmission selector
(3) Final drive
(4) Differential and bevel gear
(5) Driveshaft
(6) Transmission
(7) Transfer gears
(8) Torque converterThe transmission electronic control module (ECM) is located inside the cab, behind the operators seat. The ECM receives signals from the operator controls and speed sensors and pressure sensors on the transmission. The operator may manually shift the transmission or hold the transmission in a selected gear with the control lever.The transmission ECM regulates the shifting of gears. The ECM shifts gears by modulating the appropriate solenoid valve to engage the corresponding clutch inside the transmission. When the transmission hold control is used, the ECM will not upshift or downshift automatically unless there is an engine overspeed or underspeed condition.When the ECM performs an upshift or downshift, the ECM moves shift solenoids in the clutch control valves. The valves regulate oil flow directly down the clutches inside the transmission.The tractor has eight speeds forward and one speed reverse. Transmission (6) is controlled by an electrical system and a hydraulic system. The selection of reverse, neutral, and first speed forward is done manually. The transmission is an eight speed semiautomatic transmission.The flow of power is from the engine to drive shaft (5) and transmission transfer gears (7) to torque converter (8). Power then goes to transmission (6). In reverse, first speed forward, and second speed forward, the torque converter is in converter drive. In all other forward speeds, torque converter (8) is in direct drive. The power goes from the transmission to the differential (4). Finally, the power goes through the axles and final drive (3) to wheels.