Reference Materials - Hitachi DH 50MRY Technical Data And Service Manual

C. Grease replacement procedures
The hammering section and the gear change section use different types of grease respectively. It is not
necessary to replenish the grease unless the tool is disassembled for repair or there is a grease leakage
due to a damaged seal.
A special grease is used for the hammering section. After disassembly of the hammering section (inside the
cylinder case and the crank case), carefully wipe the old grease off the parts and fill the cylinder case and
the crank case (connecting rod side) with 70 g of grease. Take care not to overfill the grease as an
excessive amount of grease can cause hammering failure.
The gear change section (inside the gear cover) uses Hitachi Motor Grease No. 29. The proper amount of
grease is 30 g. Never use the special grease for the hammering section in the gear change section.
Otherwise, the special grease will leak into the motor section and cause subsequent troubles. Periodically
change the grease in the slip clutch. Fill the slip clutch with Hitachi Motor Grease No. 29 to the full.

REFERENCE MATERIALS

Refer to the Technical Data and Service Manual for the following model.
DH 50MB / List No. E455
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