Hitachi W 6VM Manual

TECHNICAL DATA
AND
SERVICE MANUAL
SCREW DRIVER
W 6VM
W 6V4
W 6VA4
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST Nos. W 6VM: 0798
W 6V4: E701
W 6VA4: E702
Nov. 2004
W
MODELS
W 6VM
W 6V4
W 6VA4
Hitachi 
Power Tools

Symbol Utilized
Competitor
Company Name Model Name
MAKITA 6825
C
DeWALT DW255 (DW275K)
P
REMARK:
Throughout this TECHNICAL DATA AND SERVICE MANUAL, a symbol(s)
is(are) used in the place of company name(s) and model name(s) of our
competitor(s). The symbol(s) utilized here is(are) as follows:
Model W 6VM
Symbol Utilized
Competitor
Company Name Model Name
MAKITA 6824
C
Model W 6V4
BOSCH 1404VSR (GSR6-40TE)
B
DeWALT DW272
P
Symbol Utilized
Competitor
Company Name Model Name
MAKITA 6823
C
Model W 6VA4
BOSCH 1405VSR (GSR6-25TE)
B
Milwaukee 6740-20
E

Page
CONTENTS
1. PRODUCT NAME ............................................................................................................................ 1
2. MARKETING OBJECTIVE .............................................................................................................. 1
3. APPLICATIONS ............................................................................................................................... 1
4. SELLING POINTS ........................................................................................................................... 1
4-1. Selling Point Descriptions ................................................................................................................ 2
5. SPECIFICATIONS ........................................................................................................................... 6
5-1. Specifications ....................................................................................................................................6
5-2. Optional Accessories ........................................................................................................................7
6. COMPARISONS WITH SIMILAR PRODUCTS ............................................................................... 8
6-1. W 6VM .............................................................................................................................................. 8
6-2. W 6V4 ...............................................................................................................................................8
6-3. W 6VA4 .............................................................................................................................................8
7. PRECAUTIONS IN SALES PROMOTION ...................................................................................... 9
7-1. Handling Instructions ........................................................................................................................9
7-2. Caution Plates ..................................................................................................................................9
7-3. Screw Driving-depth Adjustment .......................................................................................................9
7-4. Self-drilling Screws .........................................................................................................................10
7-5. Drywall Screws ...............................................................................................................................10
7-6. Variable-speed Switch .................................................................................................................... 11
8. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY ........................................................... 12
8-1. Disassembly ...................................................................................................................................12
8-2. Reassembly ....................................................................................................................................13
8-3. Wiring Diagrams .............................................................................................................................15
8-4. Internal Wire Arrangement and Wiring Work ..................................................................................16
8-5. Insulation Tests ...............................................................................................................................17
8-6. No-load Current Values ...................................................................................................................18
9. STANDARD REPAIR TIME (UNIT) SCHEDULES ........................................................................ 19
Assembly Diagram for W 6VM
Assembly Diagram for W 6V4
Assembly Diagram for W 6VA4

--- 1 ---
1. PRODUCT NAME
Hitachi Screw Driver, Models W 6VM, W 6V4 and W 6VA4
2. MARKETING OBJECTIVE
The Models W 6V4 and W 6VA4 screw drivers are upgraded versions of the current Models W 6V3 and W 6VA3,
equipped with strong aluminum gear cover and inner cover and ergonomical housing and handle cover with soft
grip. The Model W 6VM screw driver is newly added to respond to the increasing market demand for a screw
driver operable at 6,000 rpm. Our market share is expected to grow with the release of these new models which
broaden our lineup of screw drivers.
3. APPLICATIONS
Drywall screws: Fastening metal studs and drywall
Interior construction Installation of ceilings, paneling or partitions in offices, shops
supermarkets, apartment houses, schools, factories, etc.
Hex. and Teks screws: Fastening metal to metal, or metal to wood
Exterior construction Installation of siding on buildings
Installation of galvanized iron sheet or corrugated sheet roofing
Plate assembly Assembly and mounting of advertising billboards
Assembly of metal frames for vinyl greenhouses
Assembly and installation of automobile stamped sections
Various other interior/exterior construction and plate assembly jobs
Ergonomical design for better operation
Soft grip housing and handle cover
Big switch trigger
Soft protect cover on gear cover and
inner cover
One motion detachable locator
Class-top low noise 76 dB (A)
C: 79 dB (A)
B: 78 dB (A)
P: 82 dB (A)
E: 80 dB (A)
(Rotation direction is R.)
Class-top short length of grip
portion 206 mm (8-1/8")
C: 212 mm (8-11/32")
B: 210 mm (8-1/4")
P: 210 mm (8-1/4")
E: 208 mm (8-3/16")
High-power motor:
Class-top power input •••
U.S.A., Canada: 750 W
Other countries: 620 W
C: U.S.A., Canada: 710 W
Other countries: 570 W
B: U.S.A., Canada: 550 W
Other countries: 500 W
P: U.S.A., Canada: 740 W
Other countries: 540 W
E: U.S.A., Canada: 740 W
7.5 m (24.6 ft.) long cord
(for U.S.A., Canada, Europe, Russia and Oceania)
Robust aluminum gear
cover and inner cover
4. SELLING POINTS

--- 2 ---
4-1. Selling Point Descriptions
The new Models W 6VM, W 6V4 and W 6VA4 are more comfortable and easier to operate than the current
models and competitors. The outstanding selling points are as follows.
2) Ergonomical design for better operation
The Models W 6VM, W 6V4 and W 6VA4 are equipped with the following four parts as a result of pursuance of
the ergonomical design.
Soft grip housing and handle cover
The entire body is covered with the uniquely designed elastomer and the grip portion is uneven and matte-
finished to make it resistant to slipping. Thus the grip is very comfortable and it efficiently reduces operator
fatigue.
Table 1 Comparison of the length of grip portion
(Range covered with elastomer)
1
Maker
Model
The length of grip portion mm
HITACHI
W 6VM
206 (8-1/8") 212 (8-11/32") 210 (8-1/4")
P
Crosshatched portion:
Covered with elastomer
1) Short length of grip portion
The Models W 6VM, W 6V4 and W 6VA4 have a
handle that is shaped in good weight balance
according to the ergonomical design. In addition,
the length of the grip portion is shortest in the
class. The handle grip is very comfortable and it
efficiently reduces operator fatigue. Table 1
shows a comparison of the length of grip portion.
Maker
Model
The length of grip portion mm
HITACHI
W 6V4
206 (8-1/8")
W 6V3
218 (8-19/32") 210 (8-1/4")212 (8-11/32")
CB
Maker
Model
The length of grip portion mm
HITACHI
W 6VA4
206 (8-1/8")
W 6VA3
218 (8-19/32") 210 (8-1/4")212 (8-11/32")
CB
C
210 (8-1/4")
P
208 (8-3/16")
E
(Measuring point of the length of grip portion)
Measuring point of the
length of grip portion

--- 3 ---
Soft protect cover on gear cover and inner cover
A transparent protect cover made of elastomer is added to cover the surfaces of the gear cover and the
inner cover made of aluminum. It is easily detachable just by removing the locator. The protect cover has
the following two features.
Big switch trigger
A new big switch trigger is adopted for easier switch operation. The switch trigger is rounded for better feel
of triggering.
2
One motion detachable locator
The locator is used for adjusting the screw head depth. The current Models W 6V3 and W 6VA3 require
the operator to pull the lock sleeve and turn the locator for adjustment. The Models W 6VM, W 6V4 and
W 6VA4 are easier to adjust just by turning the locator.
W 6V4 W 6V3
3
The material of the protect cover has extremely lower thermal conductivity than aluminum. Therefore,
the protect cover lessens feeling of coldness or hotness even if the gear cover is touched with bare
hands under the severe temperature environment such as in the severely cold areas (Russia, Eastern
Europe and Northern Europe) or the severely hot areas (Middle East and South-East Asia).
The protect cover is soft because it is made of elastomer. In addition, the aluminum gear cover protects
from damages even if the Models W 6VM, W 6V4 and W 6VA4 are hit against wall materials.
(Mounting the protect cover)
Protect cover
Locator
Engage the claws in the air vents of the
housing to secure the protect cover.
Turn the locator.
4
W 6V4
W 6V3
Pull the lock sleeve in
the arrow direction.
Push the lock
sleeve in the gear
cover.
Turn the locator.
2
1
3

--- 4 ---
3) Low noise
A new fan developed by the 3-D digital analysis technology is adopted. Thanks to the optimized air passage,
the noise level of the Models W 6VM, W 6V4 and W 6VA4 is the lowest in the class. Table 2 shows a
comparison of the no-load noise level.
4) Robust aluminum gear cover and inner cover
The Models W 6VM, W 6V4 and W 6VA4 have the gear cover and the inner cover made of aluminum, while
those of the current Models W 6V3 and W 6VA3 are made of resin. This is to ensure the specified durability
and strength of the Models W 6VM, W 6V4 and W 6VA4 even under the severe environment. Table 3 shows a
comparison of the material of gear cover and inner cover.
5) 7.5 m (24.6 ft.) long cord (for U.S.A., Canada, Europe, Russia and Oceania)
The 7.5 m (24.6 ft.) long cord of the Models W 6VM, W 6V4 and W 6VA4 eliminates the inconvenience of
connecting an extension cord or carrying a cord reel in the work site.
Table 2 Comparison of the no-load noise level
Table 3 Comparison of the material of gear cover and inner cover
*: Rotational direction is R.
Maker
Model
No-load noise level* dB (A)
HITACHI
W 6VM
76 79 82
CP
Maker
Model
No-load noise level* dB (A)
HITACHI
W 6V4
76
W 6V3
79 78 79
CB
Maker
Model
No-load noise level* dB (A)
HITACHI
W 6VA4
76 78 79
CB
82
P
W 6VA3
79 80
E
Maker
Model
Material of gear cover and inner cover
HITACHI
W 6VM
Aluminum
C
Aluminum
P
Plastic
Maker
Model
Material of gear cover and inner cover
HITACHI
W 6V4
Aluminum
C
Aluminum
B
Plastic
P
Aluminum
W 6V3
Plastic
Maker
Model
Material of gear cover and inner cover
HITACHI
W 6VA4
Aluminum
C
Aluminum
B
Plastic
E
Aluminum
W 6VA3
Plastic

--- 5 ---
6) High power motor
The motor of the Models W 6VM, W 6V4 and W 6VA4 is more powerful than the current Models W 6V3 and
W 6VA3 with the class-top power input. Table 4 shows a comparison of the power input.
Table 4 Comparison of the power input
Maker
Model
HITACHI
W 6VM
750 (120 V, 6.6 A)
620
680 (120 V, 6.0 A)
540
710 (115 V, 6.5 A)
570
CB
U.S.A., Canada
Other areas
W
W
Power
input
Maker
Model
HITACHI
W 6V4
750 (120 V, 6.6 A)
620
550 (120 V, 4.8 A)
500
710 (115 V, 6.5 A)
570
CB
U.S.A., Canada
Other areas
W
W
Power
input
720 (120 V, 6.3 A)
P
W 6V3
680 (115 V, 6.4 A)
600
Maker
Model
HITACHI
W 6VA4
750 (120 V, 6.6 A)
620
550 (120 V, 4.8 A)
500
710 (115 V, 6.5 A)
570
CB
U.S.A., Canada
Other areas
W
W
Power
input
740 (120 V, 6.5 A)
E
W 6VA3
680 (115 V, 6.4 A)
600

--- 6 ---
5. SPECIFICATIONS
5-1. Specifications
Model
Capacity
Self-drilling screw
Bit mounting size
Power source
Full-load current
Power input
Switch
W 6VM
6 mm (1/4")
Single phase, AC 50 Hz or 60 Hz
U.S.A., Canada
U.S.A., Canada
Drywall screw
Type of motor
6 mm (1/4")
6.35 mm (1/4")
Single phase, AC commutator motor
6.6 A (120 V)
Other areas
2.9 A (220 V)
5.9 A (110 V) 2.8 A (230 V)
2.7 A (240 V)
750 W
Other areas 620 W
No-load rotation 0 --- 6,000 /min 0 --- 3,000 /min
Housing and handle cover ••••••••••••• Polyamide resin and thermo
plastic elastomer
Gear cover and inner cover ••••••••••• Aluminum alloy
Protect cover •••••••••••••••••••••••••••••••• Thermo plastic elastomer
Locator and hook •••••••••••••••••••••••••• Polyamide resin
Enclosure
Handle
Variable switch with reversing switch
Pistol grip handle
Weight Net •••••••••••••••1.4 kg (3.1 lbs.) (without cord)
Gross •••••••••••1.9 kg (4.2 lbs.)
Packaging*1
Cord
Type
Overall length
Two-core cabtire cable
U.S.A., Canada, Europe, Russia, Oceania ••••••••••••• 7.5 m (24.6 ft.)
Asia, Africa and other areas •••••••••••••••••••••••••••••••••• 2.5 m (8.2 ft.)
Corrugated cardboard box
Standard accessory Magnetic bit holder •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
No. 2 Phillips driver bit ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Sub-stopper •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
W 6V4 W 6VA4
0 --- 4,500 /min
*1: Packaging may vary depending on the market.
*2: Standard accessories may vary depending on the market.

--- 7 ---
Sub-stopper (B)Hex-socket
5-2. Optional Accessories
(1) For hex-head screws
Magnetic type Non magnetic type
H = 6.35 mm H = 6.35 mm
H = 7.94 mm H = 7.94 mm
H = 9.53 mm H = 9.53 mm
H = 10 mm H = 10 mm
H 1/4
H 5/16
H 3/8
Screw
head
(2) For other screws
Bit type Bit holder Sub-stopper
No.1
No.2
No.3
No.1
No.2
No.1
No.2
No.3
No.1
No.2
B size
4 mm
5 mm
B
Magnetic bit holder
(Short type)
Magnetic bit holder
Non-magnetic bit holder
Sub-stopper (G)
Sub-stopper (F)
(3) Plastic case
Optional accessories are subject to change without notice.

--- 8 ---
6. COMPARISONS WITH SIMILAR PRODUCTS
6-1. W 6VM
Maker
Model
Capacity Drywall screw
Self-drilling screw
Power
input
U.S.A., Canada
Other areas
No-load rotation
No-load noise level *1
Overall
length
Cord
length
mm
mm
W
/min
dB (A)
mm
m
W 6VM
HITACHI CP
6 (1/4") 5 (3/16")
6 (1/4")
4 (5/32")
6 (1/4")
680 (120 V, 6.0 A)750 (120 V, 6.6 A)
620
0 --- 6,000
76
328 (12-7/8")
7.5 (24.6 ft.)
710 (115 V, 6.5 A)
570
79
0 --- 6,000
302 (11-7/8")
U.S.A.: 2.5 (8.2 ft.)
Europe: 4.2 (13.8 ft.)
U.S.A.: 2.5 (8.2 ft.)
Europe: 4.2 (13.8 ft.)
310 (12-13/64")
82
0 --- 5,300
540
6-2. W 6V4
Weight *2kg
1.4 (3.1 lbs.) 1.4 (3.2 lbs.) 1.4 (3.2 lbs.)
m 2.5 (8.2 ft.)
U.S.A., Canada, Europe,
Russia and Oceania
Asia, Africa and other areas
W
---
*1: Rotation direction is R.
*2: Weight excludes cord and means actual weight.
with long bit holder
with short bit holder mm
294 (11-19/32")
Maker
Model
Capacity Drywall screw
Self-drilling screw
Power
input
U.S.A., Canada
Other areas
No-load rotation
No-load noise level *1
Overall
length
Cord
length
mm
mm
W
/min
dB (A)
mm
m
W 6V4
HITACHI C
6 (1/4") 6 (1/4")
6 (1/4")
5 (3/16")
6 (1/4")
710 (115 V, 6.5 A) 750 (120 V, 6.6 A)
620
0 --- 4,500
76
328 (12-7/8")
7.5 (24.6 ft.)
680 (115 V, 6.4 A)
600
79
0 --- 4,000
302 (11-7/8")
U.S.A.: 2.5 (8.2 ft.)
Europe: 4.2 (13.8 ft.)
302 (11-7/8")
79
0 --- 4.500
570
Weight *2kg
1.4 (3.1 lbs.) 1.3 (2.9 lbs.) 1.4 (3.2 lbs.)
m 2.5 (8.2 ft.)
U.S.A., Canada, Europe,
Russia and Oceania
Asia, Africa and other areas
W
6 (1/4")
*1: Rotation direction is R.
*2: Weight excludes cord and means actual weight.
*3: U.S.A. only. Europe, Russia and Oceania are 2.5 m.
with long bit holder
with short bit holder mm
294 (11-19/32")
BP
6 (1/4") 4 (5/32")
---
720 (120 V, 6.3 A)550 (120 V, 4.8 A)
500
78
0 --- 4,000
310 (12-13/64") 312 (12-9/32")
82
0 --- 4,000
---
1.5 (3.3 lbs.) 1.4 (3.2 lbs.)
---
W 6V3
7.5 (24.6 ft.) *3
2.5 (8.2 ft.)
268 (10-19/32")
2.5 (8.2 ft.) 2.5 (8.2 ft.)
6-3. W 6VA4
Maker
Model
Capacity Drywall screw
Self-drilling screw
Power
input
U.S.A., Canada
Other areas
No-load rotation
No-load noise level *1
Overall
length
Cord
length
mm
mm
W
/min
dB (A)
mm
m
W 6VA4
HITACHI C
6 (1/4") 6 (1/4")
6 (1/4")
5 (3/16")
6 (1/4")
710 (115 V, 6.5 A) 750 (120 V, 6.6 A)
620
0 --- 3,000
76
328 (12-7/8")
7.5 (24.6 ft.)
680 (115 V, 6.5 A)
600
79
0 --- 2,600
302 (11-7/8")
U.S.A.: 2.5 (8.2 ft.)
Europe: 4.2 m (13.8
ft.)
302 (11-7/8")
79
0 --- 2,500
570
Weight *2kg
1.4 (3.1 lbs.) 1.3 (2.9 lbs.) 1.5 (3.3 lbs.)
m 2.5 (8.2 ft.)
U.S.A., Canada, Europe,
Russia and Oceania
Asia, Africa and other areas
W
6 (1/4")
*1: Rotation direction is R.
*2: Weight excludes cord and means actual weight.
with long bit holder
with short bit holder mm
294 (11-19/32")
BE
6 (1/4")
---
---
740 (120 V, 6.5 A)550 (120 V, 4.8 A)
500
78
0 --- 2,500
320 (12-19/32") 335 (13-13/64")
80
0 --- 2,500
---
1.6 (3.5 lbs.) 1.4 (3.2 lbs.)
---
W 6VA3
2.5 (8.2 ft.)
268 (10-19/32")
2.5 (8.2 ft.) 3.0 (9.8 ft.)

--- 9 ---
7. PRECAUTIONS IN SALES PROMOTION
In the interest of promoting the safest and most efficient use of the Models W 6VM, W 6V4 and W 6VA4 electric
screwdrivers by all of our customers, it is very important that at the time of sales the salesperson carefully ensures
that the buyer seriously recognizes the importance of the contents of the Handling Instructions, and fully
understands the meaning of the precautions listed on the Caution Plate attached to each tool.
7-1. Handling Instructions
Although every effort is made in each step of design, manufacture and inspection to provide protection against
safety hazards, the dangers inherent in the use of any electric power tool cannot be completely eliminated.
Accordingly, general precautions and suggestions for the use of electric power tools, and specific precautions and
suggestions for the use of the electric screwdriver are listed in the Handling Instructions to enhance the safe and
efficient use of the tool by the customer. Salespersons must be thoroughly familiar with the contents of the
Handling Instructions to be able to offer appropriate guidance to the customer during sales promotion.
7-2. Caution Plates
The following basic safety precautions are listed on the Name Plate attached to the main body of each tool.
However, these precautions are not listed for European countries.
For Asia and Oceania
CAUTION
Read thoroughly HANDLING INSTRUCTIONS before use.
For the U.S.A. and Canada
WARNING
To reduce the risk of injury, user must read and
understand instruction manual
AVERTISSEMENT
Afin de reduire le risque de blessures, l'utilisateur doit
lire et bien comprendre le mode d'emloi.
7-3. Screw Driving-depth Adjustment
Information and suggestions for screw driving-depth selection for applicable screws are described in the Handling
Instructions. The salesperson must be thoroughly familiar with screw driving-depth adjustment procedures to be
able to instruct the customer/user in performing adjustment so that the screw neither protrudes above nor sinks
excessively below the surface of the workpiece into which the screw is driven.

--- 10 ---
Specific adjustment procedures are as follows.
(1) Head of screw protrudes above workpiece surface (Fig. 1).
If dimension A in Fig. 3 is excessively small, the head of the driven screw will protrude above the surface of the
workpiece material as shown in Fig. 1. To adjust dimension A, rotate the locator clockwise as viewed from the
screw mounting end (see Note below). Repeat adjustment as necessary until the head of the driven screw is
properly aligned with the surface of the workpiece.
(2) Head of screw sinks below workpiece (Fig. 2).
If dimension A in Fig. 3 is excessively large, the head of the driven screw will sink below the surface of the
workpiece as shown in Fig. 2. To perform adjustment, follow the procedures described in item (1) above, but
rotate the locator counter-clockwise.
Should Hex. and Teks screws be driven when dimension A is excessively large, both the screws and bits may
be easily damaged. Instruct customers/users to perform adjustment correctly without fail.
(NOTE) By turning the locator clockwise or counter-clockwise, dimension A in Fig. 3 can be adjusted
within a maximum dimension of 1.5 mm (0.059"). One complete rotation of the locator is
divided into twelve settings, each setting permitting an adjustment of 0.125 mm (0.005").
Accordingly, if dimension B in Fig. 1 is 0.25 mm (0.010"), rotate the locator by two settings.
7-4. Self-drilling Screws
Self-drilling screws are most suitable for joining wooden and metal materials, mounting metallic components onto
iron sheets, or installing roofing materials. Self-drilling and self-tapping, they are commonly employed in the
construction industry because:
Separate drilling and tapping processes are not required when securing wooden materials to metal materials.
Consequently, job costs and processes can be drastically reduced.
7-5. Drywall Screws
Drywall screws are most suitable for interior decorating and construction utilizing such materials as gypsum board
and plastic board. Their main features are:
Like Hex. and Teks screws, drywall screws are self-drilling, and can reduce work time.
Wall panels can be mounted cleanly without cracks or chips.
Drywall screws display far stronger holding power than conventional screws when applied to materials
composed of powder or particles, such as gypsum board.
Fig. 1 Fig. 2 Fig. 3
Screw
Locator
Gear cover
Sub-stopper
Material into which
screw is driven
Material into which
screw is driven
Screw Screw
B

--- 11 ---
7-6. Variable-speed Switch
This switch is equipped with a variable speed control circuit. Through the control circuit, the speed can be
controlled up to 65 % of maximum speed according to the degree at which the switch is depressed.
A disadvantage of this system is that if the bit becomes locked resulting in stoppage of the motor, the speed
control circuit may be burnt out. In such a case, the switch should be released immediately or turned OFF. To
avoid damage to the switch circuit, the customer should be advised to increase driving speed gradually until the
screw is driven approximately halfway into the workpiece, then depress the trigger to obtain optimum speed.
Fig. 4
Switch characteristics (Approximately shown converted into the linear line)
Maximum speed change point
Trigger stroke
Speed
100 %
65 %
0

--- 12 ---
8. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY
The numbers in the descriptions below correspond to the item numbers in the Parts List and exploded assembly
diagram. The [BOLD] numbers are for the Model W 6VM, the <Bold> numbers for the Models W 6V4 and
W 6VA4.
8-1. Disassembly
A. Disassembly of the parts within the handle
(1) Removal of the Handle Cover [46] <45>
Loosen the three Tapping Screws (W/Flange) D4 x 20 (Black) [47] <46>, and remove the Handle Cover
[46] <45>.
(2) Removal of the Carbon Brush (Auto Stop Type) (1 Pair) [30] <29>
With a small flat-blade screwdriver, lift up on the spring, and pull the Carbon Brush (Auto Stop Type)
(1 Pair) [30] <29> out from Brush Holder (A) [29] <28> slightly. Next, pull out the terminal portion of
Carbon Brush (Auto Stop Type) (1 Pair) [30] <29> from the Brush Holder (A) [29] <28>. Remove the
carbon brushes from both sides in the same manner.
(3) Removal of the Cord [38] <37>
After loosening the two speed control switch retaining screws, loosen the two Tapping Screws (W/Flange)
D4 x 16 [40] <39> which retain the Cord Clip [39] <38>, and remove the Cord [38] <37> together with the
Cord Armor D8.8 [37] <36>.
B. Removal of the armature and stator
(1) Removal of the Armature [21] <20>
Remove the three Tapping Screws D4 x 25 (Black) [7] <7> from the Gear Cover (A) Ass'y [8] <8>, and
remove the Inner Cover Ass'y [20] <19> with the Armature [21] <20> from the housing. And as illustrated
in Fig. 5, the Inner Cover Ass'y [20] <19> can be removed from the Armature [21] <20> by utilizing a J-130
sleeve (special repair tool, Code No. 970908) and a J-131 plate (special repair tool, Code No. 970909).
(2) Removal of the Stator [24] <23>
First, remove the Fan Guide [22] <21> from the inside of the housing.
Then, loosen the two Hex. Hd. Tapping Screws D4 x 50 [23] <22>, and lightly tap the end surface of the
Housing [36] <35> with a wooden hammer to loosen and remove the Stator [24] <23>.
Fig. 5

--- 13 ---
C. Removal of socket (A) ass'y and gear ass'y
(1) Remove Gear Cover (A) Ass'y [8] <8> and the Inner Cover Ass'y [20] <19>, then Socket (A) Ass'y [11]
<11>, Gear Set [14] <14> and Clutch Disc [12] <12> can be removed. If the Gear Set [14] <14> is hard to
remove, lightly tap the end surface of the Inner Cover Ass'y [20] <19> with a wood hammer. Be careful not
to lose the Spring [13] <13> on the outer circumference of the Gear Set [14] <14> and Washer (A) [16]
<16>. As shown in Fig. 5, insert two flat-blade screwdrivers between the Inner Cover Ass'y [20] <19> and
the Gear Set [14] <14> at each side and remove the Gear Set [14] <14> and Ball Bearing 608VVC2PS2L
[15] <15 > from the Inner Cover Ass'y [20] <19> as a single unit.
8-2. Reassembly
Reassembly can be accomplished by following the disassembly procedures in reverse. However, special
attention should be given to the following items.
(1) Fan side Ball Bearing [18] <15> for the Armature [21] <20> in the Inner Cover Ass'y [20] <19> should be
renewed in disassembling the Armature [21] <20>.
(2) Lubrication
Grease: Hitachi Motor Grease (Code No. 930035)
Application:
(a) Fill a moderate amount of grease in Gear Cover (A) Ass'y [8] <8>. (If Gear Cover (A) Ass'y [8] <8> is new,
fill it with 7 g of grease.)
(b) Outer circumference and clutch of Socket (A) Ass'y [11] <11>
(c) Teeth and clutch of the Gear Set [14] <14>
(d) Outer circumference of the Gear Set [14] <14>
(e) Clutch and inner circumference of the Clutch Disc [12] <12>
(f) Pinion of the Armature [21] <20>
Fig. 6
Inner Cover Ass'y [20] <19>
Gear Set
[14] <14>
Flat-blade screwdriver Flat-blade screwdriver

--- 14 ---
(3) Tightening torque
Handle cover retaining screws ••••••••••••••••••••••••••••••••••••••1.5 --- 2.5 N•m {15 --- 25 kg•cm (13.0 --- 21.7 in-Ibs)}
Cord clip retaining screws •••••••••••••••••••••••••••••••••••••••••••••1.5 --- 2.5 N•m {15 --- 25 kg•cm (13.0 --- 21.7 in-Ibs)}
Gear cover retaining screws ••••••••••••••••••••••••••••••••••••••••• 1.5 --- 2.5 N•m {15 --- 25 kg•cm (13.0 --- 21.7 in-Ibs)}
Stator retaining screws ••••••••••••••••••••••••••••••••••••••••••••••••1.5 --- 2.5 N•m {15 --- 25 kg•cm (13.0 --- 21.7 in-Ibs)}
Speed control switch retaining screws •••••••••••••••••••••••••••0.4 --- 0.8 N•m {4 --- 8 kg•cm (3.5 --- 6.9 in-Ibs)}
Inner cover truss screws •••••••••••••••••••••••••••••••••••••••••••••••1.4 --- 2.2 N•m {14 --- 22 kg•cm (12.0 --- 18.9 in-Ibs)}

--- 15 ---
8-3. Wiring Diagrams
(1) Products with noise suppressor
Fig. 7
(2) Products without noise suppressor
Fig. 8

--- 16 ---
8-4. Internal Wire Arrangement and Wiring Work
A. Internal wire arrangement
(1) Products with noise suppressor
Fig. 9 Schematic diagram
(2) Products without noise suppressor

--- 17 ---
(2) Wiring of variable speed control switch
Insert each cord into the terminal 1 and
terminal 2 of the speed control switch as
shown in Fig. 11, and tighten the screw
[tightening torque: 0.6 _+0.2 N•m (6 _+2 kgf•cm,
5.2 _+1.7 in-lbs.)]. Insert the lead wire (yellow)
coming from the stator into the terminal M1 and
the lead wire (white) into the terminal M2. Insert
each lead wire (white) coming from the noise
suppressor into the terminal C1 and C2. After
insertion, pull each lead wire slightly to check
the lead wires do not come off. To disconnect
the lead wires, insert a small flat-blade
screwdriver into the slots near the terminals and
pull out the lead wires.
Fig. 10 Wiring of reversing switch
(1) Wiring of reversing switch
Insert the lead wire (brown) coming from the
brush holder into the terminal (1) of the reversing
switch, and the lead wire (blue) into the terminal
(2) as shown in Fig. 10. Insert the lead wire
(gray) coming from the stator into the terminal (3)
and the lead wire (red) into the terminal (4). After
insertion, pull each lead wire slightly to check that
the lead wires do not come off. To disconnect the
lead wires, insert a small flat-blade screwdriver
into the slots near the terminals and pull out the
lead wires.
B. Additional wiring work
General internal wiring can be accomplished by referring to paragraph 8-3 and 8-4-A. The following are special
instructions for switch connection.
Fig. 11 Wiring of speed control switch
8-5. Insulation Tests
On completion of reassembly after repair, measure the insulation resistance and conduct the dielectric strength
test.
Insulation resistance: 7 M Ωor more with DC 500 V Megohm Tester
Dielectric strength: AC 4,000 V/1 minute, with no abnormalities •••••••• 220 V --- 240 V ( and 110 V for U.K. products )
AC 2,500 V/1 minute, with no abnormalities •••••••• 110 V --- 127 V (except for U.K. products)