Hitachi CJ 18DA User manual

PRODUCT NAME
18 V Cordless Jig Saw
Model
135 mm (5-5/16”) CJ 18DA
REPAIR GUIDE ---------------------------------------------------------------------------------------------------------------- 1
1. Precautions on disassembly and reassembly ----------------------------------------------------------- 1
• Disassembly ---------------------------------------------------------------------------------------------------- 1
• Reassembly ---------------------------------------------------------------------------------------------------- 4
• Lubrication points and type of lubricant ------------------------------------------------------------------ 5
• Tightening torque ---------------------------------------------------------------------------------------------- 6
• Checking after reassembly --------------------------------------------------------------------------------- 6
• Wiring diagram ------------------------------------------------------------------------------------------------- 7
CONTENTS
C
CONFIDENTIAL
Sep. 2020
Overseas Sales Management Dept.
Page

-1-
Fig. 1
WARNING: Be sure to remove the battery from the main body before starting repair or maintenance
work. If the switch is activated inadvertently with the battery still mounted on the main
body, the motor may turn unexpectedly and could cause serious injury.
1. Precautions on disassembly and reassembly
[Bold] numbers in the description below correspond to the item numbers in the parts list and exploded
assembly diagram for the Model CJ 18DA.
1. Removal of the base
Loosen the Hex. Socket Hd. Bolt M5 x 18 [53] and remove the Base [43] together with the Base Locker [52]
from the Gear Holder Ass’y [47].
2. Removal of the lever
Loosen the Tapping Screw (W/Flange) D3 x 20 [12] and remove the Lever [10], Lever Spring [9], and
Washer [11].
3. Disassembly of housing (A).(B) set
(1) Loosen two Tapping Screws (W/Flange) D4 x 20 (Black) [7] and remove the Grip Cover [5] from Housing
(A).(B) Set [1].
(2) Loosen eight Tapping Screws (W/Flange) D4 x 20 (Black) [7] and remove housing (B) (name plate is
affixed) of Housing (A).(B) Set [1].
(3) Remove the Switch Terminal Set [3], Pushing Button [2], and Guard Bar [8] from housing (A).
Disassembly
REPAIR GUIDE
[52]
[53]
Fig. 2
[9]
[10]
[11]
[12]

-2-
Fig. 3
Fig. 4
4. Disassembly of the plunger ass’y
(1) Remove the D6 Pin [46] from the Gear Holder Ass’y [47]. Remove Plunger Holder (A) [31] from the
plunger ass’y.
(2) Loosen two Seal Lock Hex. Socket Hd. Bolts M3 x 6 [18] and remove the Plunger Cover [17] and Plunger
(A) [32].
(3) Remove Plunger Holder (B) [21] (with the Spring Plate [20] and Spring (C) [19] attached), Packing [22],
and Washer (A) [23] from Plunger (B) [25]. Remove Spring (C) [19] from Plunger Holder (B) [21] and
turn the Spring Plate [20] by 90° to remove Plunger Holder (B) [21].
(4) Remove the Retaining Ring D15 [24] from Plunger (B) [25] and pull out the Holder Cover [30] downward.
Remove the Holder Spring [29] holding the position where Plunger (B) [25] is inserted with pliers
carefully not to damage the Holder Spring [29].
NOTE: Be careful not to let the Plunger Piece [28] and Spring (C) [27] pop out when removing the
Holder Spring [29]. Be careful not to lose Spring (C) [27] and Needle Roller (C) [26].
[7]
[5]
[1]
[32]
[8]
[3]
[2]
[17] [31]
[18]
[19]
[25]
[26]
[20]
[27]
[28]
[29]
[30]
[21]
[22]
[23]
[24]

-3-
Fig. 5
5. Removal of the gear holder
(1) Pull out Connecting Piece (A) [33] and Needle Bearing [34] from the Gear [36].
(2) Remove the Retaining Ring for D7 Shaft [35] from the tip of the spindle.
(3) Remove the Gear [36], Balance Weight [37], Orbital Cam [38] and Washer (A) [23] in this order.
(4) Remove the Motor [13] press-fitted in the Gear Holder Ass’y [47].
(5) Remove the Retaining Ring (E-type) for D5 Shaft [39], Change Knob [42], Spring (C) [27], and Steel
Ball 5/32 [41].
NOTE: Be careful not to lose Spring (C) [27] and Steel Ball 5/32 [41].
(6) Pull out the Needle Roller D4 x 24 [40] press-fitted in the Gear Holder Ass’y [47]. Remove the Roller
Holder [49] and Needle Roller [48].
[33]
[39]
[36]
[23]
[13]
[34]
[35]
[38]
[27]
[46]
[37]
[42]
[41]
[47]
[49]
[40]
[48]

-4-
Fig. 6
Perform reassembly by reversing the disassembly procedure. However, special attention should be given
to the following items.
1. Mounting the change knob
Mount Spring (C) [27] and Steel Ball 5/32 [41] to the inside of the Change Knob [42] as described below.
(1) Apply grease (Nippeco SEP-3A) to the Steel Ball 5/32 [41], and then put the Steel Ball 5/32 [41] in the
concave portion as shown in the figure below.
(2) Put Spring (C) [27] in the Change Knob [42]. Mount the Retaining Ring (E-Type) for D5 Shaft [39] while
pushing Spring (C) [27] against the Steel Ball 5/32 [41].
(3) Check the Change Knob [42] for any abnormality by moving it.
2. Reassembly of the plunger ass’y
(1) Put the Spring Plate [20] in Plunger Holder (B) [21] and mount Spring (C) [19] to it.
(2) Mount the Retaining Ring D15 [24], Washer (A) [23], Packing [22], and Plunger Holder (B) [21] to
Plunger (B) [25] in this order.
(3) Pressing the concave portion of Plunger (B) [25] against the portion under the slotted hole on Plunger
(A) [32], fit the D3 pins on the Plunger Cover [17] in the holes on Plunger (A) [32] and fix it by tightening
two Seal Lock Hex. Socket Hd. Bolts M3 x 6 [18].
(4) Fit the tip of the Plunger Piece [28] in Spring (C) [27] and put Needle Roller (C) [26] in Spring (C) [27].
Insert the Plunger Piece [28] into Plunger (B) [25] aligning the U-shape protrusion on the Plunger Piece
[28] with the U-shape groove on Plunger (B) [25].
(5) Insert the inner tip of the Holder Spring [29] in the 1 mm diameter hole on Plunger (B) [25] while pressing
the Plunger Piece [28]. At this time, check that the Plunger Piece [28] is securely retained by the Holder
Spring [29].
(6) Match the outer tip of the Holder Spring [29] with the groove on the Holder Cover [30]. Turn the Holder
Cover [30] by about 120° to insert it into Plunger (B) [25]. At this time, check that the groove on the
Holder Cover [30] is positioned over the flange of Plunger (B) [25].
(7) Fit the Retaining Ring D15 [24] in the groove of the Holder Cover [30].
Reassembly
[27]
[
41
]
[
42
]
[
39
]

-5-
Fig. 7
Apply specified amount of grease to the following portions.
Nippeco SEP-3A grease
• Entire circumference of the Gear [36], particularly its teeth
• Both sides of Washer (A) [23] (under the Orbital Cam [38])
• Both sides and holes of the Orbital Cam [38]
• Both sides and holes of the Balance Weight [37]
• Outer circumference of Connecting Piece (A) [33]
• Tooth flank of the Motor [13]
• Outer circumference of the Steel Ball 5/32 [41]
• Entire circumference of Plunger (A) [32]
Molub-Alloy No. 777-1 grease
• Inner diameter portion of the gear ass’y (grooves for grease and inner circumference of the needle
bearing: 0.5 g)
• Inner circumferences of Connecting Piece (A) [33] and Needle Bearing [34] (0.5 g)
• Sliding portion of the gear ass’y and the Balance Weight [37]
Nippeco BC-4 grease
• Contact surfaces of the Spring Plate [20] and Plunger (B) [25] (0.5 g)
Please purchase the following grease as necessary.
Item Registered part name Net weight Code No.
Molub-Alloy No. 777-1 Grease (Molub-Alloy No. 777-1) 75 g 75 g 325149
Nippeco SEP-3A Grease (SEP-3A) 100 g 100 g 930035
Grease (SEP-3A) 2.5 kg 2.5 kg 930038
Nippeco BC-4 Grease (Nippeco BC-4) 75 g 75 g 372814
[31]
[
17
]
[
32
]
[
18
]
[25]
[
19
]
[
26
]
[
20
]
[29]
[
27
]
[
30
]
[
28
]
[
21
]
[24]
[
22
]
[
23
]
Lubrication points and type of lubricant

-6-
Item
No. Part name No. used
Tightening torque
N•m kgf•cm
[7] Tapping Screw (W/Flange) D4 x 20 (Black) 10 1.96±0.49 20±5
[12] Tapping Screw (W/Flange) D3 x 20 10.88±0.10 9±1
[18] Seal Lock Hex. Socket Hd. Bolt M3 x 6 22.45±0.49 25±5
[45] Special Bolt 4 2.76±0.29 28±3
[50] Machine Screw (W/Washer) M4 x 5 1 1.73±0.29 18±3
[53] Hex. Socket Hd. Bolt M5 x 18 14.91±0.49 50±5
Check the following after reassembly.
(1) Check that the operation of the switch of the Switch Terminal Set [3] and the Pushing Button [2] is
normal.
(2) Check that the LED light turns on when the switch trigger of the Switch Terminal Set [3] is pulled.
(3) Check that the number of strokes of the blade can be adjusted depending on the amount the switch
trigger is pulled.
(4) Check that the saw blade is securely mounted.
(5) Check that the battery level indicator lamp turns on and off by pressing the battery level indicator switch.
Checking after reassembly
Tightening torque

-7-
Fig. 8 • Wiring diagram
Connect the internal wires correctly as illustrated in the diagrams below. If the internal wires are incorrectly
connected, the motor may not turn or other problems could occur.
A
(Europe, Australia, and New Zealand)
Wiring diagram
Red internal wire
(soldering)
Black internal wire
(soldering)
A
1 turn
Red internal wire
(soldering)
Black internal wire
(soldering)
Red mark:
+ terminal side
125.1±0.2

-8-
Fig. 9 • Connecting diagram
SGT
FET
(–)
(+)
M2
M1
Black
Red
M
Black
Red
Black
Red
White
Red
White
Noise suppressor
Battery terminal
DC-speed control switch
Co
ntr
o
l
u
nit
R
e
v
e
r
s
in
g
u
nit
Indicator ass’y
–
LD
+
SGT
FET
(–)
(+)
M2
M1
Black
Red
M
Black
Red
Black
Red
White
Red
White
Noise suppressor
Battery terminal
DC-speed control switch
Co
ntr
o
l
u
nit
R
e
v
e
r
s
in
g
u
nit
Indicator ass’y
–
LD
+
Ferrite core
For Europe, Australia, and New Zealand

A
Rev.1 CJ18DA
A
501 502 503 505
506
1
2
3
14
13
8
5
6
9
10
11
12
18
19
20
21
22
23
24
25
27
28
29
30
17
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
4
15
16
507
509
510
508
504
511
512
7
23
27
26

ITEM CODE NO.
NO. NO. USED
*1 376450 HOUSING (A).(B) SET 1
*1 376450M HOUSING (A).(B) SET 1 FOR USA, CAN
2 336856 PUSHING BUTTON 1
3 376452 SWITCH TERMINAL SET 1
*4 376029 BATTERY BSL 1850C (EUROPE, AUS, NZL) 2 INCLUD. 502
*4 376314 BATTERY BSL 1850C (THA) 2 INCLUD. 502
5 376482 GRIP COVER 1
6 NAME PLATE 1
7 301653 TAPPING SCREW (W/FLANGE) D4 X 20 (BLACK) 10
8 376484 GUARD BAR 1
9 376481 LEVER SPRING 1
10 375856 LEVER 1
11 333916 WASHER 1
12 332929 TAPPING SCREW (W/FLANGE) D3 X 20 1
13 376451 MOTOR 1
*14 376459 INTERNAL WIRE (BLACK) L230 1 EXCEPT FOR EUROPE, GBR, AUS, NZL
*15 376458 INTERNAL WIRE (RED) L230 1 EXCEPT FOR EUROPE, GBR, AUS, NZL
*16 376457 INTERNAL WIRE FERRITE SET 1 FOR EUROPE, GBR, AUS, NZL
17 376473 PLUNGER COVER 1
18 325077 SEAL LOCK HEX. SOCKET HD. BOLT M3 X 6 2
19 376476 SPRING (C) 1
20 376475 SPRING PLATE 1
21 376487 PLUNGER HOLDER (B) 1
22 376474 PACKING 1
23 376467 WASHER (A) 2
24 376480 RETAINING RING D15 1
25 376472 PLUNGER (B) 1
26 376604 NEEDLE ROLLER (C) 1
27 982454 SPRING (C) 2
28 376479 PLUNGER PIECE 1
29 376478 HOLDER SPRING 1
30 376477 HOLDER COVER 1
31 376470 PLUNGER HOLDER (A) 1
32 376471 PLUNGER (A) 1
33 332829 CONNECTING PIECE (A) 1
34 325242 NEEDLE BEARING 1
35 994251 RETAINING RING FOR D7 SHAFT 1
36 376466 GEAR 1
37 376469 BALANCE WEIGHT 1
38 376468 ORBITAL CAM 1
39 673489 RETAINING RING (E-TYPE) FOR D5 SHAFT 1
40 376683 NEEDLE ROLLER D4 X 24 1
41 335297 STEEL BALL 5/32 (10 PCS.) 1
42 338992 CHANGE KNOB 1
43 375854 BASE 1
44 375855 BASE PLATE 1
45 321996 SPECIAL BOLT 4
46 376460 D6 PIN 1
47 376464 GEAR HOLDER ASS'Y 1 INCLUD. 27, 39-42, 48, 49
48 983545 NEEDLE ROLLER 1
49 376465 ROLLER HOLDER 1
50 375857 MACHINE SCREW (W/WASHER) M4 X 5 1
51 321576 RUBBER BUSHING 1
52 339663 BASE LOCKER 1
53 372724 HEX. SOCKET HD. BOLT M5 X 18 1
501 CHARGER (MODEL UC 18YFSL) 1
502 329897 BATTERY COVER 1
503 944458 HEX. BAR WRENCH 4 MM 1
504 338997 SPLINTER GUARD 1
505 879357 JIG SAW BLADES NO. 41 (5 PCS.) 1
506 376454 CASE ASS'Y 1
507 337108 CASE ASS'Y (STACKABLE 3) 1 INCLUD. 508-510
508 336472 LATCH 4
509 336473 HANDLE 1
510 336474 HINGE 2
*511 370492 DUST COLLECTOR 1 FOR EUROPE, GBR
512 376455 INNER TRAY 1
601 321593 GUIDE 1
602 339018 SUB BASE 1
603 370492 DUST COLLECTOR 1
604 930035 GREASE (SEP-3A) (100 G) 1
DESCRIPTION REMARKS
OPTIONAL ACCESSORIES
STANDARD ACCESSORIES

ITEM CODE NO.
NO. NO. USED
DESCRIPTION REMARKS
605 372814 GREASE (NIPPECO BC-4) 75 G 1
606 325149 GREASE (MOLUB-ALLOY NO. 777-1) 75 G 1
607 879336 JIG SAW BLADES NO. 11 (5 PCS.) 1
608 879337 JIG SAW BLADES NO. 12 (5 PCS.) 1
609 879338 JIG SAW BLADES NO. 15 (5 PCS.) 1
610 879339 JIG SAW BLADES NO. 16 (5 PCS.) 1
611 879340 JIG SAW BLADES NO. 21 (5 PCS.) 1
612 879341 JIG SAW BLADES NO. 22 (5 PCS.) 1
613 963400 JIG SAW BLADES NO. 97 FOR STAINLESS (5 PCS.) 1