Hydraulic valve lash adjustment

MAN is developing a maintenance-free valve gear for use in industrial engines,
through the use of hydraulic valve clearance adjustment.

Hydraulic valve lash adjustment from MAN Engines

In many industrial applications the cylinder head cover is difficult to access, meaning it is also difficult to adjust the valves. In some cases, extensive disassembly work is required on the vehicles or engine attachments to be able to check the valve clearance. In many future applications, the installation space above the engine will be used for increasingly sophisticated exhaust gas aftertreatment systems, or the engine itself will be integrated into an ever-smaller installation space. The use of a maintenance-free valve gear negates the need to check or adjust the valve clearance. Customers additionally benefit as there is no need for disassembly or maintenance work, and they have greater freedom in how to use the installation space above the cylinder head.


  • prevents increased fuel consumption

  • no service

  • less cost

  • quiet running

The hydraulic valve clearance adjustment is provided for the following series


How works the hydraulic valve clearance adjustment

Due to its design and operating principle, using pressurised oil, a spring force and a small ball valve, the hydraulic compensation element compensates any play in the valve train.

All tolerances and any play in the valve train are compensated over the operating time of the motor by a small cylindrical component (hydraulic valve clearance adjustment) which acts like a hydraulic piston.