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GENERAL:
Before attempting disassembly of the PULLMASTER Model M12 planetary winch with freespooling, the following
instructions for disassembly and reassembly should be read and understood:
It is suggested that all expendable parts, such as O-rings and oil seals, are not reused on reassembly. It is
therefore important to have a seal kit (Part No. 23123) and, providing the hydraulic motor has to be serviced,
a seal kit (Part No. 23121) on hand before the unit is taken apart. Two new needle bearings item 875, may also
be required (Part No. 25723).
NOTE:
Back up washers may be included with seal kit. Install with oil seals as per instructions. If not present
in seal kit, the oil seals supplied do not require back up washers.
A clean working area is of prime importance, similar to conditions used for service work on any other hydraulic
component. All parts, as they are removed from the winch assembly, should be inspected for wear and damage.
Worn or damaged parts must be replaced. Thoroughly clean parts before reassembly. Do not use solvent to clean
the brake friction plates.
During reassembly, lubricate all O-rings and oil seals with grease before installation.
In the following service instructions, reference to parts is made by numbers and shown on the applicable group
drawings.
DISASSEMBLY
For the majority of required service or repair work, disassembly is required only on the brake housing of the
PULLMASTER Model M12 planetary winch with freespooling. There are no special tools needed for the service
or repair work and no adjustments or calibrations are necessary. Proceed with the disassembly as follows:
DISASSEMBLY OF HYDRAULIC MOTOR ASSEMBLY:
If the analysed service or repair work requires access to the interior of the brake housing, the hydraulic motor
should not be disassembled. In this case, the hydraulic motor should be removed together with the motor adaptor
as a complete assembly. If a problem has been analysed to be in the hydraulic motor, proceed with the
disassembly as follows:
1) Remove four hex capscrews item 951, together with lockwashers item 953, from motor assembly.
IMPORTANT:
Failure to exercise care when removing the motor port end cover or gear housing could
permanently damage the machined surfaces of these motor components. Take care not
to damage machined surfaces of motor components at disassembly.
2) Remove (pry loose if necessary) port end cover item 870, together with bearings item 875, and ring seal item
877. Thrust plate item 885, and dowel pins item 865, may stay in gear housing.
3) If thrust plate comes off with end cover, carefully pry it off of bearings item 875, and discard pocket seals item
887.
4) Remove gear set item 881, which consists of two gears which are a matched set.
5) Carefully pry gear housing item 861, off of motor adaptor item 800. Thrust plate item 885, and dowel pins
item 865, may stay in gear housing.
6) If thrust plate stays on motor adaptor, carefully pry it off of bearings item 875, and discard pocket seals item 887.
7) Discard body seals item 869. It is also advisable to replace ring seals item 877, at this time. Bearings item
875, must be removed to allow access to ring seals.
Pocket seals, body seals, and ring seals in the hydraulic motor assembly are not part of the winch seal kit. The
seal kit for the hydraulic motor can be ordered from the factory under Part No. 23121. All parts of the hydraulic motor,
256 REV.030718
SERVICE INSTRUCTIONS
