Hitachi WH 10DAL, Service Manual, Page: 3 / 12

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Fig. 5 • Disassembly of the hammer assembly
Raised face of hammer
Steel Balls D5.556 [10]
Steel ball guide groove
Spindle [16]
Push down.
Washer (S) [14]
J-297 base for washer (S)
Hammer Spring (E) [13]
Stopper (A) [15]
Top of spindle cam
Hammer [11]
Spindle [16]
2. Removal of the exterior parts
(1) Insert a small flat-blade screwdriver between the Front Cap [6] and Hammer Case [7] , and then
remove the Front Cap [6] from the Hammer Case [7] .
3. Removal of housing (A).(B) set
(1) Remove the eight Tapping Screws (W/Flange) D3 x 16 (Black) [35] to remove housing (B) from the
Housing (A).(B) Set [29] .
(2) Remove the Hammer Case [7] , hammer assembly, Ring Gear [21] , Motor DC 12V [23] and Switch
Terminal Set [33] as one unit. Remove Pushing Button (A) [32] .
4. Disassembly of the hammer assembly
(1) Mount the hammer assembly onto the J-297 base for washer (S) (a special tool). With a hand press,
push down the top of the Spindle [16] to compress Hammer Spring (E) [13] . In this position, remove
Stopper (A) [15] with a small flat-blade screwdriver, and then release the hand press.
(2) Remove the hammer assembly from the J-297 base for washer (S) and support the end surface of the
Spindle [16] . With a hand press, push down either of the raised faces of the Hammer [11] to compress
Hammer Spring (E) [13] . In this position, extract the two Steel Balls D5.556 [10] from the cam grooves
of the Spindle [16] and Hammer [11] with a small flat-blade screwdriver.
(3) Slowly release the hand press and lift the Hammer [11] and Washer (S) [14] together to extract both
from the Spindle [16] . Remove Hammer Spring (E) [13] .
5. Disassembly of the switch terminal set
Disconnect the internal wires (red and black) coming from the Motor DC 12V [23] from the Switch
Terminal Set [33] by unsoldering.
NOTE: Do not remove the switch and controller from the Switch Terminal Set [33].