MAN Engines

Hydraulic valve clearance adjustment

Hydraulic valve clearance adjustment
In focus:

Maintenance-free valve train for industrial engines

MAN is developing a maintenance-free valve train and is relying on the use of hydraulic valve clearance adjustment.

Hydraulic valve clearance adjustment from MAN Engines

In many industrial applications, the cylinder head cover is difficult to access and thus adjustment of the valves is only possible under difficult conditions. In some cases, this requires extensive disassembly of the vehicles or engine components in order to carry out a valve clearance check. In many future applications, the installation space above the engine will be used for increasingly complex exhaust aftertreatment systems, or the engine itself will be integrated into ever smaller installation spaces. A maintenance-free valve train eliminates the need to check and adjust the valve clearance. Additional customer benefits arise from the elimination of disassembly and maintenance activities, as well as flexible use of the installation space above the cylinder head.


  • avoids increased fuel consumption
  • no maintenance
  • lower costs
  • quiet running

Hydraulic valve clearance adjustment is available for the following series

  • D0834
  • D0836
  • D1556
  • D2676
  • D3876
  • D4276

Functioning of the hydraulic valve clearance adjustment

The hydraulic compensating element (HVA element) takes over the compensation of all occurring clearances in the valve train through its design and mode of operation, using pressure oil, spring force and a small ball valve.

Here, all tolerances as well as the occurring clearances in the valve train are compensated during the running time of the engine by a small cylindrical component (HVA), which acts like a hydraulic piston.