Hitachi WF 4V User manual

POWER TOOLS
TECHNICAL DATA
AND
SERVICE MANUAL
AUTOMATIC SCREW DRIVER
WF 4V
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No. 0783 Nov. 1999
W
MODEL
WF 4V

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:
Symbols Utilized Competitors
Company Name Model Name
MAKITA 6830
C

Page
CONTENTS
[ Business Section ]
1. PRODUCT NAME •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
2. MARKETING OBJECTIVE ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
3. APPLICATIONS ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
4. SELLING POINTS •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
4-1. Selling Point Descriptions •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 2
5. SPECIFICATIONS •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 4
5-1. Specifications ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 4
5-2. Standard Accessories ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 4
5-3. Optional Accessories •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 5
6. COMPARISONS WITH SIMILAR PRODUCTS ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 6
6-1. Specification Comparisons •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 6
6-2. Characteristics Comparisons ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 6
7. PRECAUTIONS IN SALES PROMOTION •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 7
7-1. Safety Instructions •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 7
7-2. Precautions in Sales Promotion ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 7
[ Service Section ]
8. TROUBLESHOOTING ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 10
8-1. Troubleshooting Guide •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 10
9. PRECAUTIONS IN DISASSEMBLYAND REASSEMBLY•••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 12
9-1. Disassembly and Reassembly of the Feeder Unit and Handling Precautions •••••••••••••••••••••••••••• 12
9-1-1. Disassembly ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 12
9-1-2. Reassembly ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 12
9-1-3. Tightening Torque ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 13
9-1-4. Confirmation After Reassembly ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 13
9-2. Precautions in Disassembly and Reassembly of the Main Body ••••••••••••••••••••••••••••••••••••••••••••••• 13
9-2-1. Disassembly ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 13
9-2-2. Reassembly ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 15
9-2-3. Insulation Tests ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 20
9-2-4. No-load Current Value •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 20
10. STANDARD REPAIR TIME (UNIT) SCHEDULES ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 21
[ Appendix ]
Assembly Diagram for WF 4V •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 22
Notice for use
Specifications and parts are subject to change for improvement.
Refer to Hitachi Power Tool Technical News for further information.

--- 1 ---
Tool-less detachable collated screw feed attachment
Two kinds of uses, as a collated screwdriver and an
impact driver
Capable of retightening protruded screws
1. PRODUCT NAME
Hitachi Automatic Screwdriver, Model WF 4V
2. MARKETING OBJECTIVE
This machine is an impact type screwdriver designed for use with collated screws. The screw feed attachment at
the head of the machine is detachable without tools. The Model WF 4V is also capable of driving ordinary bolts
and wood screws that are not collated and retightening protruded screws. The new functions and higher
performance of this multi-purpose screwdriver which uses Hitachi's innovative technology assure greater demand
and increased sales in this category of products.
3. APPLICATIONS
Continuous drywall screw driving by using collated screws or screw strips
Driving various individual screws and bolts with the collated screw strip attachment removed
Drilling holes into various materials
4. SELLING POINTS
Can be use as a drilling tool by
removing the screw feed attachment
(with use of Drill Chuck Adapter Set).
Impact method permits screws with small
recoil force to be driven.
Easy work due to small holding force
Less damage to screw heads

--- 2 ---
In Fig. 2, the solid line indicates the screw tightening load
applied with the impact mechanism, and the broken line a
typical load required with the conventional claw clutch system.
As the screw is tightened, tightening torque rises with the
screw's pushing into the work. Increasing downward pressure
is required when the screw slips off the tape because, on the
one hand, the clutch cannot be disengaged without such force
and on the other hand, the bit and the screw cannot be
separated apart otherwise. Both could be reasons for
incomplete driving when insufficient pressure is applied.
First referring to the claw clutch system, since the clutch
disengaging torque is strong, increasing pressure must be
applied to the screw as it is pushed in, because the clutch
claws would otherwise disengage, making further screw
tightening impossible. As a result, the required force goes on
rising, as indicated by the dotted line, until screw tightening is
finished.
Screw position
Load
4-1. Selling Point Descriptions
(1) An impact mechanism that allows screw tightening with a smaller thrust, plus our unique collated screw feed
attachment
The WF 4V employs an impact mechanism which is capable of tightening screws with a smaller thrust than
with the claw clutch system used for competitors' screwdrivers. The way it works is schematically illustrated
in Fig. 2.
With the impact system, on the contrary, it is sufficient to apply only enough force to keep the bit and screw
together, because hammering impact provides the necessary torque as the tightening torque increases, with
no need for the operator to increase pressure against the workpiece. The load indicated by solid line in Fig. 2
should be enough for optimum tightening. However, the actual load required will be such as indicated by the
chain line in Fig. 2 because it is very difficult for operators to take the force off as soon as the screw slips off
the tape.
(2) The WF 4V can be used as an impact screwdriver by removing the collated screw feed attachment:
For re-tightening jobs or other operations
Spring load
Pressure force of claw
clutch system
Pressure force of
impact mechanism
Slipping force
of tape
Fig. 2

--- 3 ---
(3) The collated screw feed attachment can be removed without tools.
Tool-less detachment is possible for the collated screw feed attachment, making bit replacement and re-
working much easier. This improved operability of the WF 4V will be a great selling point because the
competitors' collated screw feed attachments must be secured by means of a hexagon socket head cap screw
or the like.
Note: Ensure that the power plug is disconnected from the receptacle prior to the attachment removal.
1. Hitachi WF 4V 2. C
Attachment mechanism
Instructions
Holding the main unit with one hand, turn the
collated screw feed attachment with the other
in the direction indicated by the arrow in Fig.
3-1. Register the mark on the main unit with
the mark on the attachment and remove by
pulling it in the direction indicated in Fig. 3-2.
Loosen the hexagonal socket head bolt
securing the casing with a hexagonal wrench
and remove by pulling it in the direction
indicated by the arrow.
Fig. 3-2
Fig. 3-1
Fig. 3-3
Hexagon socket
head cap screw
Casing
mark
mark mark
mark
mark

--- 4 ---
5. SPECIFICATIONS
5-1. Specifications
Table 1
Capacity
Single phase AC: 50/60 Hz
Voltage: 240 and 230 V
Tightening torque
D4 x 25-41 mm (5/32" dia. x 1" --- 1-5/8")
Collated screw strips (50 screws)
Note 1) Max. 1,000 kgf•cm [98 N•m] (72.3 ft-lb)
Dihedral width: 6.35 mm (1/4") for Hex. Bit inserting
Tip configuration
Type of motor
Enclosure
Type of switch
Handle configuration
Full-load current
Overall length x height
5-2. Standard Accessories
(1) Philips bit [Code No. 313880]
(2) Belt guide [Code No. 314283]
(3) Rubber cover (B) [Code No. 314629]
(4) Hook [Code No. 307343]
(5) Plastic case [Code No. 306854]
Impact rate
Single-phase AC commutator motor
Without cord
Packaged
Packaging
Standard accessories
Weight
Type and number of screws
Power supply
Power input
No-load rotation speed
Center height
Housing: Polyamide resin
Slider (A), (B) and (C): Polycarbonate resin
Slider Case (A) and (B): Polycarbonate resin
Belt Guide (A) and (B): Polycarbonate resin
Variable speed trigger switch with forward/reverse changeover lever
D-type
1.3 A (240 V) and 1.4 A (230 V)
300 W
0-2,300 /min.
0-3,400 /min.
1.8 kg (4.0 lbs.)
3.8 kg (8.4 lbs.)
Corrugated cardboard box [with plastic case]
354 mm (13-15/16") x 197 mm (7-3/4")
26 mm (1-1/64")
Philips bit •••••••••••••••••••1 pc.
Belt guide •••••••••••••••••••1 pc.
Rubber cover (B) •••••••• 1 pc.
Hook ••••••••••••••••••••••••• 1 pc.
Plastic case •••••••••••••• 1 pc.
Note 1) Based on tightening an M12 (15/32") bolt (Strength Grade: 12.9) for 3 sec. with a hexagon socket.

--- 5 ---
5-3. Optional Accessories
The optional parts listed below can be used when the collated screw feed attachment has been removed.
Phillips bit
50 mm (2")
Bit No.
No. 2
No. 3
Code No.
992671
992672
Hexagon socket
L
B
Stamped figures
9961778 (5/16")65 (2-9/16")8
Stamped figures
5 mm Hexagon socket
Part Name L
(mm) B (mm) Code No.
98532910 (3/8")65 (2-9/16")106 mm Hexagon socket
99617812 (15/32")65 (2-9/16")125/16" Hexagon socket
99617913 (1/2")65 (2-9/16")138 mm Hexagon socket 99618014 (9/16")65 (2-9/16")1410 mm Hexagon socket (small type)
99618116 (5/8")65 (2-9/16")1610 mm Hexagon socket
99618217 (21/32")65 (2-9/16")1710 mm Hexagon socket 99619721 (13/16")166 (6-17/32")211/2" Hexagon long socket
Woodworking drill bit (Code No. 959183)
14 mm dia.
(35/64")
83 mm (3-17/64")
Fig. 4
Fig. 5
Table 2
Table 3
Fig. 6
Drill chuck adapter set (Code No. 996195)
The drill chuck adapter set permits mounting of various types of locally - available drill bits for a variety of drilling
operations.
Fig. 7

--- 6 ---
6. COMPARISONS WITH SIMILAR PRODUCTS
6-1. Specification Comparisons
Table 4
Hitachi
WF 4V
4 (5/32")
25 --- 41 (1" --- 1-5/8")
300
0 --- 2,300
1.8 (4.0 lbs.)
(1.85) (4.08 lbs.)
82
Impact type
345
--- 354
(13-19/32" --- 13-15/16")
197 (7-3/4")
76 (3")
17.2 [1.69 N•m]
(1.24 ft-lb)
Plastic case
Phillips bit
Hook
Rubber cover (B)
Belt guide
Maker/Model
Item
Capacity: Screw size
Screw length
Power input
No-load speed
Weight (without cord)
(Actual weight)
No-load noise level
Tightening torque
structure
Dimensions
Height
Width
Moment from
centroid to grip
Standard accessories
Unit
mm
mm
W
/min.
kg
dB
mm
mm
mm
kg•cm
C
4 (5/32")
25 --- 40 (1" --- 1-9/16")
470
0 --- 4,700
1.9 (4.2 lbs.)
(1.97) (4.34 lbs.)
82
Clutch type
334 --- 342
(13-5/32" --- 13-19/32")
191 (7-17/32")
76 (3")
18.7 [1.83 N•m]
(1.35 ft-lb)
Plastic case
Phillips bit
Hook
Hex. bar wrench
Hitachi
W 4YF
4 (5/32")
20 --- 41 (25/32" --- 1-5/8")
430
4,000
1.8 (4.0 lbs.)
(1.78) (3.92 lbs.)
82
Clutch type
345 --- 361
(13-19/32" --- 14-7/32")
135 (5-5/16")
80 (3-5/32")
23.4 [2.29 N•m]
(1.69 ft-lb)
Plastic case
Phillips bit
Hook
Top adjuster No.1
Top adjuster No.2
Hitachi
WF 4DY
4 (5/32")
25 --- 41 (1" --- 1-5/8")
DC 12V
0 --- 2,000
2.0 (4.4 lbs.)
(2.04) (4.50 lbs.)
70
Impact type
369
--- 378
(14-17/32" --- 14-7/8")
202 (7-15/16")
73 (2-7/8")
17.4 [1.71 N•m]
(1.26 ft-lb)
Plastic case
Phillips bit
Hook
Charger
Battery
6-2. Characteristics Comparisons
6-2-1. Defect Rate Comparison
While defect rates depend on manufacturing irregularity of screws, materials to be tightened and operator's skill,
reference data at the factory testing result are shown below.
<Testing conditions>
Testing method: Perform positioning by gently applying the tip end of the main unit to the material
to be tightened and tighten by applying further pressure.
The material to be tightened: Plasterboard 9.5 (3/8") (T9.5 (3/8") x 2 for 40 mm (1-9/16") + base of
Japanese hemlock)
Screw size
Table 5
25 mm (1")
40 mm (1-9/16")
Hitachi
WF 4V
0.20 %
0.20 %
C
0.40 %
1.80 %
Length

--- 7 ---
7. PRECAUTIONS IN SALES PROMOTION
7-1. Safety Instructions
In the interest of promoting the safest and most efficient use of model WF 4V by all 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 and Nameplate attached to each tool.
A. Handling Instructions
Although every effort is made in each step of design, manufacture and inspection to provide protection against
any 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,
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.
B. Nameplate
Each tool is provided with a Nameplate which lists the following basic safety precautions in the use of the tool:
(1) For Europe (except Germany), Australia and New Zealand
CAUTION
Read thoroughly HANDLING INSTRUCTIONS before use.
(2) For Germany
ACHTUNG
Bedienungsanleitung vor Inbetriebnahme lesen.
7-2. Precautions in Sales Promotion
Ensure that the following precautions are taken for sales promotion of this unit.
7-2-1. Precautions When Using the Main Body
(1) Use the specified genuine bit.
Using any bit other than the one specifically designed for the automatic screwdriver WF 4V may lead to
incompletely tightened or improperly fed screws, so ensure that your customers do not use any bit other than
that specified.
(2) Do not lubricate the main unit.
Ensure that the main unit is never lubricated because this may lead to improper operation or other troubles. If
the slider section is lubricated, if first moves smoothly but plasterboard powder gradually sticks to the oil,
making the slider movement sluggish. Ensure that the plasterboard powder deposited around the slider is
frequently cleaned away with compressed air before the slider movement becomes slow.

--- 8 ---
(3) Setting for collated screws
Ensure that the first one of the collated screws is set to the
screw mark on the slider. If the screws are set otherwise
than indicated in Fig. 8, the plasterboard surface may be
scratched by the bit (because of insufficient feed of the
screw series) or screws may be wasted (because of
excessive feed of the screw series).
(4) Plasterboard powder deposited on the slider surface and on the roller on top of the slider as shown in Fig. 9
may result in improper operation. Ensure that these parts are frequently cleaned with compressed air before
the slider movement becomes slow.
Likewise, plasterboard powder deposited on the mounting ends of the collated screw attachment may make
removing and mounting difficulty. Ensure these parts
are cleaned frequently. (In particular, the powder tends
to easily stick when working with the screwdriver held
upward.)
(5) The small hole on either side of the handle section is important for ventilating gases. Ensure that this hole is
not blocked.
(6) Reference for tightening depth
This screwdriver is designed to adjust the tightening depth by turning the Knob. Ensure that the tightening
depth is adjusted following the procedure given below so that the screws are properly tightened without such
errors as the screw head remaining above the plasterboard surface or sunk below it after tightening.
(a) Screws (L) 25 mm (1") --- 32 mm (1-1/4") [using top adjuster No.1 (small)]
(b) Screws (L) 35 mm (1-3/8") --- 41 mm (1-5/8") [using top adjuster No. 2 (large)]
Screw mark
Fig. 8
Slider Roller
Slider case
Fig. 9
Counterclockwise
Clockwise
Set the stopper at "25 - 32".
Knob
Fig. 10-1
Set the stopper at "35 - 41".
Fig. 10-2

--- 9 ---
Correct (Flush)
Test drive a screw, and if the
screw head is still protruding,
adjust by turning the Knob
counterclockwise.
If the screw head is too deep,
turn the Knob clockwise.
Protruded Sunk
Fig. 10-3
In this unit, unlike other automatic screwdrivers, the bit keeps on turning after completely tightening the screw.
Therefore, the screw head may be damaged when the bit moves away from the screw. So visually observe
how the screw is tightened, in addition to adjusting the tightening depth with the Knob mentioned above.
7-2-2. Tightening Posi-Drive Screws
Advise your customers that to tighten Posi-Drive Screws, they should use only the optional Posi-Drive Screw Bit
specially designed for the WF 4V. As for the WF 4V, as the bit engages the screw while it's turning, the use of
conventional Posi-Drive Screw Bits, which are not designed for this type of service, may result in cracked or
rounded out screws as screw driving may proceed without complete engagement of the bit with the screw.
To prevent this, the Posi-Drive Screw Bit designed for use with the WF 4V is provided with a guide point at its tip
(Fig. 11). However, the service life may be comparatively shorter than that of conventional Phillips Bits because
the bit wings must be made comparatively smaller.
Guide point Wings
Fig. 11

--- 10 ---
8. TROUBLESHOOTING
8-1. Troubleshooting Guide
Symptom
Screws protrude from the
workpiece surface.
Screw jamming.
Screws are not fed.
No.
1
2
3
Probable Cause
Faulty stopper adjustment.
Improper driver bit being used.
Driver bit excessively worn.
Thrust against workpiece is insufficient.
Screws other than those specified are used.
Strip contains defective screw(s).
Defective collating strip (deformed or cut).
Screws are missing.
<Collated screw strips>
Specified screws not used.
Defective screws used (bent screws, foreign
matter in slots of screw head, defective
collating).
Screws or collating tape are snagged or
scraping.
Collating tape is deformed or cut.
<Feeder unit>
Sprocket pawl is damaged.
Link piece is damaged.
Test
Turn knob counterclockwise and test drive
screw.
Check length of driver bit.
[Length = 114 mm (4-1/2")]
Check for wear at the face of the driver bit.
Check pressure during driving.
Check if specified screws are used.
Check if specified screws are properly
mounted.
Disassemble and check.
Remedy
Turn knob and adjust to correct scale setting.
Instruct operator to use genuine HITACHI
Driver Bits.
Replace driver bit.
Instruct operator to apply enough force to
engage screws and driver bits completely.
Use specified screws.
Replace defective screws.
Use specified screws.
Replace defective screws.
Replace defective parts.

--- 11 ---
Probable Cause
Too high sliding resistance of slider ass'y (C)
Too high sliding resistance of sprocket ass'y
Collated screw strips are not properly set into
the slider groove and belt guide.
Belt guide groove burred or clogged with dust.
Top adjuster not appropriate for screw length.
Specified screws not used.
Defective screws used (foreign matter in slots
of screw heads or defective collating strip).
Too high sliding resistance of slider
Too high sliding resistance of slider ass'y (C)
Broken or weak slider spring
Remedy
Remove burrs or clean out dust.
Replace defective parts.
Set screws correctly.
Remove burrs or clean out dust.
Install appropriate top adjuster for the
screw length
Refer to Item 3.
Refer to Item 3.
Remove burrs or clean out dust.
Replace defective parts.
Replace defective parts.
Symptom
Screws are not fed.
Screws are bent during
driving.
Slider does not return.
No.
3
4
5
Test
Disassemble and check.
Check if the collated screw strip is properly
set in its groove.
Check groove for burring or clogging.
Check screw length and top adjuster.
Refer to Item 3.
Refer to Item 3.
Disassemble and check.
Disassemble and check.

--- 12 ---
9. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY
The [Bold] numbers in the following descriptions correspond to the item numbers in the parts list of the Model
WF 4V.
9-1. Disassembly and Reassembly of the Feeder Unit and Handling Precautions
9-1-1. Disassembly
(a) Loosen the four Tapping Screws (W/Flange) D4 x 20 [13] securing Slider Case (A) [12] and remove Slider
Case (A) [12] from Slider Case (B) [12]. With Slider Case (A) [12] removed, the built-in parts and assemblies
can be taken out as they are.
* Since Spring (A) [11] is fitted in compression, removing Slider Case (A) [12] will cause the Slider Ass'y to
jump out. So be sure to hold the Slider Ass'y while loosening the Tapping Screw (W/Flange) D4 x 20 [13] to
prevent it from jumping out. Also take care not to lose the Roller [10] housed in the Slider Case.
(b) Loosen the two Tapping Screws (W/Flange) D4 x 25 [4] securing the Sprocket [3], Spring (B) [8], SliderAss'y
(C) [1], Bit Guide [6] and Slider (B) [1] and remove them.
9-1-2. Reassembly
Simply reverse the disassembly procedure, while observing the following precautions.
(1) Make sure that the joint between the Slider (A)/(B) is completely aligned at the point marked (a) in Fig. 13 (as
this is essential for proper sliding).
(2) If the top surface (b) (Fig. 13) of the screw seat of Slider Case (A) is lower than Slider Case (B), it is likely to
result in improper sliding movement. Adjust top surface (b) of the screw seat of Slider Case (A) to be flush
with or a little higher than Slider Case (B).
Fig. 12
[1]
[2] [3]
[4]
[5]
[6][7] [8] [9] [10] [11] [12]
[13]
[14]
[15]
[16]
[17]
Slider Case (A)
Slider Case (B) Slider (B)
Slider (A)
ba
Fig. 13

--- 13 ---
9-1-3. Tightening Torque
(1) Tapping Screw (W/Flange) D4 x 20 (25/32") •••••• 20 5 kg•cm [1.96 0.49 N•m] (1.44 0.36 ft-lb)
(2) Tapping Screw (W/Flange) D4 x 25 (1") •••••• 20 5 kg•cm [1.96 0.49 N•m] (1.44 0.36 ft-lb)
9-1-4. Confirmation After Reassembly
(1) Make sure that the Slider Ass'y moves smoothly within the Slider Case [12].
(2) Make sure that the collated screws feed correctly.
(3) Make sure that there are no lost or tilted screws when actually tightening.
9-2. Precautions in Disassembly and Reassembly of the Main Body
9-2-1. Disassembly
(1) Remove Handle Cover and Housing (B).
Remove the four Tapping Screws (W/Flange) D4 x 20 (25/32") secured to the Handle Cover. Then insert a
cutter along the joint between Housing (A) and Handle Cover, cut the Grip Tape [45] and remove the Handle
Cover. Remove the eight Tapping Screws (W/Flange) D4 x 20 (25/32") secured to Housing (B). After Housing
(B) has been removed, the parts inside can be removed individually or subassemblies.
(2) Removal of mechanical parts
Lift Housing (A) while holding Anvil (M) [29] and Ball Bearing [39] of Spindle (A), and the Anvil section and
Hammer (A) [31] and Spindle (A) [38] sections can be separated from each other. Then remove the Second
Pinion Ass'y. Take care not to lose Washer (A) [40].
(a) Remove Anvil (M) [29]
Follow the procedure as shown on the next page to remove the Retainer Ring [18], Retainer [19], Guide
Spring [20] and Guide Sleeve (A) [21] in this order. Take care not to lose the two Steel Balls [28] [3.175
mm dia. (1/8")] fitted in the hole of Anvil (M) [29].
Hold the body and place a small slotted (flat-blade)
screwdriver at an angle to the Retainer and Retaining
Ring at the retaining ring gap.
Press down on the Retainer and Retainer Ring
with the screwdriver at the same angle.
Fig. 14-2
Fig. 14-1
12
Small slotted (flat-blade) screwdriver
Anvil (M) [29]
Retaining Ring [18]
Retainer [19]
Retaining ring gap Guide Sleeve (A) [21]

--- 14 ---
Next, slide the screwdriver into the gap and under
one side of the Retaining Ring.
Slowly raise the Retaining Ring using the end face
of the Guide Sleeve as a fulcrum.
Fig. 14-4
Fig. 14-3
34
With one side of the Retainer Ring opening raised, slowly lift the rest with a small slotted (flat-blade)
screwdriver to remove the Retainer Ring and Retainer. Do it slowly as quick action may cause the
Retainer Ring [18] to jump out.
(b) Removal of Spring
Compress Spring [34] at one of the lugs at the Hammer end by hand and also Stopper (A) [35] (rubber) at
end face of Hammer (A) [31]. While maintaining the pressure, pull out the Steel Ball [30] [5.55 mm dia.
(7/32")] under the cam groove in Spindle (A) [38] and Hammer (A) [31] with a small slotted (flat-blade)
screwdriver and remove it from the Steel Ball receiving groove. Then release the pressure and pull
Hammer (A) [31] and Washer (G) [33], holding them together, out of Spindle (A) [38], and the Spring [34]
can be removed.
Fig. 15
Steel ball guide groove
Hammer (A) [31]
Spindle (A) [38] Lugs of hammer
Top of the spindle cam
Steel ball D5.556 [30]

--- 15 ---
9-2-2. Reassembly
Simply reverse the disassembly procedures while observing the following precautions.
(1) Anvil section
(a) Insert Anvil (M) [29] with the chamfered inner diameter section of Washer (F) [27] facing the Anvil vane.
(b) Insert the Rubber Washer [26] and the Metal D20 x 16 [24] and its Oil Seal 12 x 18 x 3 [22] so that grease
will not leak from inside.
(c) Fit the two Steel Balls [28] [3.175 mm dia. (1/8")] into the hole in Anvil (M) [29] and assemble Guide Sleeve
(A) [21], the Guide Spring [20] and the Retainer [19] in this order. Then fit the Retainer Ring [18] into the
Anvil groove.
(Note) Assemble with the stepped portion of the Retainer [19] facing the forward end.
(2) Hammer and spindle section
(a) Press-fit the Gear [37] from the top of the Spindle, insert Washer (A) [36] and fit it into the groove of
Spindle (A) [38] with the chamfered face of Stopper (A) [35] facing up. Then insert the Spring [34], and
with 21 Steel Balls [32] [3.97 mm dia. (5/32")] and Washer (G) [33] placed in the Hammer, keep on the
Hammer with Spindle (A) [38] contacted.
(b) Bring the apex of the cam groove provided in Spindle (A) [38] in Fig. 15 on page 14 into alignment with the
Steel Ball receiving groove in Hammer (A) [31]. Press down by hand one of the lugs at the Hammer end to
compress Spring [34], and compress Stopper (A) [35] at end face of the Hammer (A) [31] until it rests on
Spindle (A) [38] to support it.
(c) Fit the two Steel Balls [30] [5.55 mm dia. (7/32")] into the Steel Ball receiving groove. After making sure
that the Steel Balls are in the cam groove, release the pressure to complete assembly.
(3) Assembly of mechanical parts into Housing (A)
(a) Spline the Anvil (M) [29] with its assembly parts shown in Fig. 16 to the Spindle and install in Housing (A).
Fit Washer (A) [40] behind the Ball Bearing [39].
(b) Insert Ball Bearing (B) [48] into the Gear (second pinion) [37] and install in Housing (A) so that the gears
mesh.
Fig. 16
Steel Balls D3.175 [28]
Guide Sleeve (A) [21]
Retaining Ring [18]
Guide Spring [20]
Retainer [19]
Note: Orient the roughened
end toward the tip. Oil Seal 12 x 18 x 3 [22]
Note: Be careful to orient
the direction of the tip.
Note: The chamfered side of
the bore of Washer (F) [27]
must face toward the wings
of the Anvil.
Metal [24]
Rubber Washer [26] Washer (F) [27]
Anvil (M) [29]

--- 16 ---
(5) Housing section
(a) Lubrication
Before mounting the hammer, spindle and anvil sections, apply silicone rubber (ThreeBond 1211)
(Code No. 306927) to the shaded areas shown in Fig. 18 to ensure grease sealing.
(b) When replacement of Housings (A) and (B) is not required, apply silicone rubber (ThreeBond 1221)
(Code No. 306927) to the Oil Seal 12 x 18 x 3 [22] and the spigot joint section (projection) of Housing (A)
(shaded areas in Fig. 19) to ensure grease sealing.
Fig. 18
Application area Application area
Housing (B) Housing (A)
Fig. 19
Application area Application area
Housing (B) Housing (A)
Application area

--- 17 ---
Fig. 20
(Brown)
(Cord)
(Cord)
(Blue)
(Carbon brush)
(Stator)
(Noise suppressor) Red
Yellow
Brown
(Cord)
(Cord)
Blue
(Carbon brush)
(Stator)
Brown
Brown
Blue
Red
Brown
Red
(Noise suppressor)
(Stator)
(Stator)
Fig. 21 Fig. 22
(6) Wiring of switch
General internal wiring can be accomplished by referring to step (7). The following are special instructions for
switch connection.
(a) Disconnection of reversing switch wiring
As illustrated in Fig. 20, insert a small flat-blade
screwdriver into the slots near the terminals and pull out
the lead wires.
(b) Disconnection of variable-speed control switch wiring
As illustrated in Fig. 22, insert a small flat-blade
screwdriver into the slots near the terminals and pull out
the lead wires in the same manner as illustrated in
Fig. 20.
(c) Wiring of reversing switch
As illustrated in Fig. 21, insert the lead wire (brown) coming from the stator into the terminal marked "(1)" of
the reversing switch, and the lead wire (yellow) into terminal "(2)".
Insert the lead wire (brown) coming from the carbon brush into the terminal "(3)" and the lead wire (brown)
into the terminal "(4)". After insertion, pull each lead wire slightly to check that the lead wires do not come
out.
(d) Wiring of the variable-speed control switch
Insert each cord into the terminal marked "1 " and terminal "2 " of the speed control switch as shown in
Figs. 20 and 22, and tighten the screw (tightening torque: 2.5 --- 3.0 kg•cm). Insert the lead wire (blue)
coming from the stator into the terminal marked "M1" and the lead wire (red) into terminal "M2". Insert
each lead wire (red) coming from the noise suppressor into the terminals C1 and C2. After insertion, pull
each lead wire slightly to check that the lead wires do not come out.