Periodic service of forest cranes

A forest crane, like all machinery, requires regular service.
Carrying out cyclic inspections prevents the occurrence of potential faults, and thus guarantees the failure-free operation of the equipment.

Below, we present a universal inspections schedule that is worth implementing.
Nevertheless, we recommend that you consult the manual of the machine in question for more detailed information.


  1. Check the hydraulic lines, cylinders and connections
  2. Make sure that the crane arm does not drop by itself
  3. Check the screw connections of the new machine daily
  4. After finishing work, clean the machine paying attention to possible damages/leaks


  1. Check the oil level in the rotation column, remember not to exceed the MAX* mark. If necessary, add oil when the engine has cooled down.

* The MAX oil gauge is also used to fill the oil turn column.

  1. Check the connections of the arms and actuators – the pins should be well lubricated, and the fasteners should be firmly attached without play
  1. Check the side play of the extension arm – if it is too large, adjust it by tightening the sliding pads on both sides of the extension arm simultaneously until the play disappears
  1. Check the chain of the extension arm – lift the crane, fully extend and retract the extension arm, and if necessary, adjust the chain by loosening one of the tensioners and tensioning the other. Pay special attention to this, because when the chain is too tight, the gears and bearings are damaged / worn out faster.
  1. Check the harvester grapple/harvester head – perform min. 10 turns to ensure that the oil in the rotator and hoses returns to the tank. In addition, check the tightening torque of the screw 1 of the rotator head – the screw should be tightened with the appropriate torque in accordance with the instruction manual
  1. Grease the crane arms

Lower and rest the crane on the ground so that the hydraulic system and connections are not strained, then use a grease nipple to lubricate the slewing column, boom and cylinder joints (use grease and oil for open surfaces, never those with molybdenum sulphide) and the outer surfaces of the booms when fully extended crane.

Unscrew the end cover of the JIB (stork) and lubricate it in two positions – fully extended and fully retracted.

Also lubricate the chain by adding oil to the grease nipple at the fill point in the JIB cover.


1. Clean the crane – if you use a pressure washer to clean it, do not direct the stream directly at the rotation column, so that water does not get there

2. Check the structure of the crane

• inspect the column and arms for damage and cracks

• check cylinder mountings, they should be tight fit and well lubricated

• inspect the hydraulic system, in particular the hydraulic hoses, which should not show signs of wear

• check connections and rotator

3. Check the tightening torques of the screws, which can be found in the instruction manual

4. Check the clearances of the extension arm – insert the arm, check the front washers, then unscrew the front cover of the JIB and check the rear washers


1. Change the oil in the rotation column

• unscrew the drain plug (3) and drain the oil into the container

• after draining the oil, screw in the drain plug

• remove the MAX indicator (1) and add oil until it reaches the MAX level

• spin

2. Check the magnetic plug of the rotator which catches metallic oil particles

• Lower the grapple/head to the ground

• unscrew and clean the plug

• screw the plug with the correct torque

• turn the equipment 10 full revolutions in one direction for a complete oil cycle

3. Clean the extension chain

• remove the chain by disconnecting the upper fastener (2)

remove the wheel and bearing, pull and spread over the surface of the second arm

• disconnect the lower chain attachment (4)

• pull the extendable arm outwards


  1. Adjust the rotator suspension brake – the connection consists of a washer (B), a screw (A) and the whole thing is secured with a nut (C)

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