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
- Cam disc
- Rollers
- Pressure valves
- Pressure limiting valve
- Control valve cover
- Oil pressure and temperature sensor
- Differential Electronic Module (DEM)
- Control valve/axial solenoid
- Accumulator
- Oil strainer
- Electrical feed pump
- Oil filter
- Suction valves
- Piston pump
- Working piston
- Wet disc package
- Bearings
- Compression springs
Active On demand Coupling (AOC) can be explained as a hydraulic pump.
The basic pressure in the system is built up by the electrical feed pump. This way the axial pistons are pressurized with oil so that they are pressed against the cam disc via the rollers. The axial piston builds up a working pressure which is conducted to the working piston via the pressure valves. This pressure creates a fixed connection between the input and output shafts. The maximum pressure is limited by the pressure limiting valve. The difference in speed between the input and output shafts is proportional in accordance with the oil pressure to the axial pistons. A large difference in speed between the input and output shafts provides high oil pressure to the axial pistons. The same speed on the input and output shafts provides lower oil pressure to the axial pistons. The oil pressure on the clutch driven plates is controlled by the control valve. The axial solenoid controls the control valve. A closed control valve provides maximum pressure to the clutch driven plates, which provides maximum power transmission. An open control valve provides minimum pressure to the clutch driven plates, which provides a limited power transmission.
The accumulator maintains the basic pressure in the system. The oil filter keeps the oil free from dirt and small particles which can damage the system.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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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