Set Clutch Parts 5-speed SMG (3.0)

The shift solenoid valves (marked ‘PPV’) are responsible for engaging the gears in the SMG gearbox. There are two of these pressure-proportional valves mounted on the hydraulic unit. Working in conjunction with the selection valve, they operate the shift actuator. If either valve is faulty, the car may be unable to engage one or more gears.

The pressure accumulator is responsible to store the pressure of the hydraulic system for later access by the actuators. This piston type accumulator has two cells: one cell storing the hydraulic fluid and one cell containing a Nitrogen gas filling which creates the counterpressure. Both cells are separated by a moving piston. Typical symptoms of a faulty pressure accumulator are frequent and short pump cycles. If there is no more preload pressure left in the accumulator, the pump runs every few seconds, which ultimately leads to a consequential damage of the pump motor. Along with the pump motor, a faulty pressure accumulator is one of the most common causes of pressure build-up issues and is one of the few wear parts in the system that should be regularly checked and replaced if necessary.

We offer a brand-new replacement accumulator.