Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Hydraulic Function, Overview
| 1 | Hub with cam curve | 11 | Electrical feed pump. |
| 2 | Rollers | 12 | Oil filter |
| 3 | Check valves, exhaust side | 13 | Check valve, intake side |
| 4 | Pressure limiting valve | 14 | Piston pump |
| 5 | Control valve/axial solenoid | 15 | Operating piston |
| 6 | Oil pressure and temperature sensor | 16 | Wet plate unit |
| 7 | Differential electronic module (DEM) | 17 | Bearing |
| 8 | Control valve/axial solenoid | 18 | Pressure springs |
| 9 | Accumulator | 19 | Combined check and by-pass valve |
| 10 | Oil screen |
The Active On demand Coupling (AOC) can be described as a hydraulic pump.
The basic pressure is generated by the electronic feed pump. This pressurizes the annular pistons with oil so that they are pressed against the hub's cam curve via rollers. The annular pistons generate a working pressure which is led to the operating piston via the check valves on the intake side. This pressure creates a fixed connection between the input and output shafts. The maximum pressure is limited by the pressure limiting valve. Large differences in speed on the input and output shafts enable the annular pistons to create an oil flow. The oil flow is less if the input and output shafts are at the same speed. The oil flow, created by the annular pistons, is controlled by the control valve, which in turn is controlled by the axial solenoid. A closed control valve produces high pressure, which causes maximum pressure on the clutch driven plates. This produces a maximum power transmission. An open control valve produces low pressure, which causes minimum pressure on the clutch driven plates. This produces a limited power transmission.
The accumulator maintains the basic pressure in the system. The oil filter keeps the fluid clean by filtering dirt and small particles which could damage the system.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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