Hitachi WH 12DM2 Technical Data And Service Manual page 36

(2) Removal of Front Cap (A) [5] <1> and Protector (A) [6] <2>
Insert a small flat-blade screwdriver between Front Cap (A) [5] <1> and Protector (A) [6] <2> and remove
them from the Hammer Case [8] <4>.
(3) Removal of the Hammer Case [8] <4> and the hammer assembly
Remove the four Tapping Screws (W/SP. Washer) D4 x 25 (Black) [7] <3> that connect the Hammer Case [8]
<4> with Housing (A). (B) Set [35] <32> and remove the Hammer Case [8] <4> and the hammer assembly
from Housing (A).(B) Set [35] <32>.
(4) Disassembly of the hammer assembly
Spindle (D) [18] <15>
Hammer Spring
(D) [15] <12>
Stopper [17] <14>
Remove the hammer assembly from the J-297 base for washer (S) and support the end surface of Spindle (D)
[18] <15>. With a hand press, push down either of the raised faces of Hammer (D) [12] <9> to compress
Hammer Spring (D) [15] <12>. In this position, extract the two Steel Balls D5.556 [11] <8> from the cam
grooves of Spindle (D) [18] <15> and Hammer (D) [12] <9> with a small flat-blade screwdriver. Then, slowly
release the hand press and lift Hammer (D) [12] <9> and Washer (S) [16] <13> together to extract them from
Spindle (D) [18] <15>. Hammer Spring (D) [15] <12> can then be removed.
Spindle (D) [18] <15>
Hammer (D) [12] <9>
(5) Removal of the Hook Ass'y [42] <38>
Remove the Special Screw M5 [49] <45> with a flat-blade screwdriver or a coin and remove the Hook Ass'y
[42] <38> and the Hook Spring [48] <44>.
Push down.
Washer (S) [16] <13>
J-297 base for washer (S)
Fig. 2
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Raised face of hammer
Top of spindle cam
Fig. 3
Mount the hammer assembly onto
the J-297 base for washer (S).
With a hand press, push down the
top of Spindle (D) [18] <15> to
compress Hammer Spring (D) [15]
<12>. In this position, remove the
Stopper [17] <14> with a small flat-
blade screwdriver, then release the
hand press. (See Fig. 2.)
Steel Ball D5.556 [11] <8>
Steel ball guide groove