Auto 4WD Mode Power Flow
WARNING: This page is about a different car, the 2023 GMC Sierra 3500 HD and 2023 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Callouts in the following chart represent components shown in graphic above.
| Callout | Component Name |
|---|---|
| 1 | Transfer Case Input Shaft |
| 2 | Transfer Case Scissor Mechanism Lever |
| 3 | Transfer Case Four Wheel Drive Clutch |
| 4 | Transfer Case Front Output Shaft Drive Chain Assembly |
| 5 | Transfer Case Rear Output Shaft |
| 6 | Transfer Case Two/Four Wheel Drive Actuator Shaft Gear |
| 7 | Transfer Case Front Output Shaft |
| 8 | Transfer Case Two/Four Wheel Drive Actuator Cam |
During the Auto 4WD mode, the power flow is the same as it is in the 4HI mode. Except, during the Auto 4WD mode, the 2/4 wheel drive actuator assembly (13) rotates the control actuator shaft to the correct torque level positions. Rotating the control actuator shaft to the various positions changes the clutch torque level. When a difference of front wheel speed to rear wheel speed is recognized, the transfer case control module commands for more or less clutch torque.