CAMSHAFT 3S3491 - Caterpillar

To avoid striking overpasses, electrical power lines and obstructions, always lower the body before moving the machine.
The machine must be stopped and engine at low idle before changing directions.After moving the shift lever, do not accelerate until after hearing or feeling the transmission clutches engage.
Illustration 1 g01519384
(1) Transmission control Make sure that the machine is stopped and that the engine is at low idle when you move the transmission control to the P position. When the transmission control is in the P position, the transmission is in neutral and the parking brake is engaged. When the transmission control is in the N position, the transmission is in neutral, the parking brake are not engaged, and the wheels are free to roll.Make sure that the machine is stopped and that the engine is at low idle when you change direction between forward and reverse, or between reverse and forward.When the machine is at a stop and the transmission control is moved to any forward selection, first gear is engaged. Below ground speed of approximately 6 km/h (4 mph), the machine will be in torque converter drive.When the engine accelerates and the ground speed increases, the transmission automatically upshifts. Above ground speed of approximately 6 km/h (4 mph) and during other forward gears, the lockup clutch will be engaged. Then, the machine is in direct drive. During shifts, the machine will be in torque converter drive.While the machine is in motion, moving the transmission control to a higher forward selection will not force an upshift. Shifting of the transmission is governed by ground speed.When the ground speed and the engine speed are reduced by an increased load or by deceleration, the transmission automatically downshifts. The transmission downshifts one gear at a time in order to select the correct gear.A downshift inhibitor prevents the machine from forcing a downshift. When the machine is in motion and the transmission control is moved to a lower forward selection, the transmission will not force a sudden downshift. The transmission will not downshift until the proper ground speed is achieved.Shift Inhibiting
The Transmission Electronic Control Module (ECM) performs most of the transmission control and torque converter lockup functions. The Chassis ECM receives input signals that describe the position of the body and the position of the transmission control. These input signals are sent to the Transmission ECM. The input signals are used to control the shifting of the transmission and torque converter lockup.Shifting is limited in the following situations: limiting machine speed, engine overspeed protection, coasting in neutral, management of directional shifts, limiting top gear, reverse neutralizer and limiting body up gear.Reference: See Service Manual, "Transmission Electronic Control System" for additional information.Limiting Machine Speed
Cold Mode for the Transmission - This limits the top gear of the machine until the oil temperature in the transmission reaches operating temperature range. When the oil temperature in the transmission is below 40 °C (104 °F), the transmission will not shift above FIRST gear.Engine Overspeed Protection
If the engine speed reaches 2100 rpm,