KOKI WH 18DE (01) PDF MANUAL

WARNING: Always remove the battery from the main body before starting repair or maintenance work. Because the tool is cordless, inadvertently activating the switch with the battery left in the main body will start the motor rotating unexpectedly, and could cause serious injury.

When troubleshooting, be sure to wipe off all dust, water, and other foreign matter from the internal parts, and then dry the parts adequately before conducting the investigation.

If the motor does not run, check the following:

Possible Cause	Check Method	Corrective Action
Switch connector cable poorly inserted	Check the insertion status of connector cable. (See “1. Reassembly of the power supply unit”.)	Reinsert connector cable.
Rotor pinion ass’y magnet poorly adhered	Check whether the rotor pinion ass’y magnet is inserted to the same level as the rotor core edge.	Replace the rotor pinion ass’y.
DC-speed control switch breakdown	Check the board surface for any silicon peelings, device damage, and drop dents. Check the metal terminals (pin) in the switch connectors for corrosion.	Replace the DC-speed control switch.
Wiring ass’y breakdown	Check the board surface for any urethane peelings, device damage, and drop dents.	Replace the wiring ass’y.

If the rotor does not switch direction, check the following:

Possible Cause	Check Method	Corrective Action
Switch connector cable poorly inserted	Check the insertion status of connector cable. (See “1. Reassembly of the power supply unit”.)	Reinsert connector cable.
Faulty switch connectors	Check the conductor of the connector cable for corrosion. Check the metal terminals (pin) in the switch connectors for corrosion.	Replace the DC-speed control switch and the wiring ass’y.
Imperfect contact in the switch	If the connector cable of the wiring ass’y and the switch connector are trouble-free.	Replace the DC-speed control switch.

If the rotating speed does not rise or cannot be changed, check the following:

Possible Cause	Check Method	Corrective Action
Wiring ass’y breakdown	Check the board surface for any urethane peelings, device damage, and drop dents.	Replace the wiring ass’y.
Switch connector cable poorly inserted	Check the insertion status of connector cable. (See “1. Reassembly of the power supply unit”.)	Reinsert connector cable.
Faulty switch connectors	Check the conductor of the connector cable for corrosion. Check the metal terminals (pin) in the switch connectors for corrosion.	Replace the DC-speed control switch and the wiring ass’y.
Imperfect contact in the switch	If the connector cable of the wiring ass’y and the switch connector are trouble-free.	Replace the DC-speed control switch.

If the LED light does not go on, check the following:

Possible Cause	Check Method	Corrective Action
Wiring ass’y breakdown	Use a fully charged battery and operate the light switch to check whether the LED light goes on.	Replace the wiring ass’y.

1. Use a small flat-blade screwdriver to remove the Retaining Ring [1]. Insert the edge of the screwdriver under the end of the Retaining Ring [1]. Align the opening of the Retaining Ring [1] with the notch on the Anvil [9]. Secure the body. Slowly raise the Retaining Ring [1] from the end to remove it from the Anvil [9]. NOTE: Do not remove them too quickly. Be careful not to let the Retaining Ring [1] pop up, and do not lose the two Steel Balls D3.5 [8] in the opening of the Anvil [9]. Hold Washer (D) [2] and Guide Spring [3] with fingers to prevent them from popping up together with the Retaining Ring [1]. 2. Remove Washer (D) [2]. 3. Remove Guide Spring [3]. 4. Remove Guide Sleeve [4].

1. Insert the edge of a small flat-blade screwdriver into the space between the Front Cap [5] and the Hammer Case [6], and remove the Front Cap [5] from the Hammer Case [6]. 2. Remove the Truss Hd. Screw M4 (Black) [33] and the Hook [34]. The Hook [34] need not be removed, but is removed here to facilitate disassembly work.

1. Remove the two Tapping Screws (W/Flange) D3 x 16 (Black) [32] from the Tail Cover [31] and then remove the Tail Cover [31]. 2. The Rotor Pinion Ass’y [27] has strong magnetic force. Securely support Housing (A).(B) Set [29] and pull out the Rotor Pinion Ass’y [27] in the direction of “B” as shown in the diagram.

1. Remove the eight Tapping Screws (W/Flange) D3 x 16 (Black) [32]. Remove housing (B) of Housing (A).(B) Set [29]. Then, remove the Strap (Black) [40] (Model WH 18DE only). 2. Remove the Hammer Case [6], hammer assembly, Inner Cover [26], and Wiring Ass’y [35] (including the DC-Speed Control Switch [36]). Remove the Pushing Button [37].

1. Remove Washer (E) [22], two Needle Rollers [19], and Idle Gear Set (2 pcs.) [17] from the hammer assembly detached from the Hammer Case [6]. 2. Set the hammer assembly on the J-297 base for washer (S) (Code No. 317063). 3. Press down on the end of the Spindle [18] with a hand press to keep Hammer Spring (J) [13] compressed. 4. Use a small flat-blade screwdriver to take out Stopper (C) [15]. Release the hand press. 5. Remove the hammer assembly from the J-297 base for washer (S) and support the end surface of the Spindle [18]. 6. Press down on the raised faces of the Hammer [10] with a hand press to keep Hammer Spring (J) [13] compressed. 7. Remove two Steel Balls D5.556 [16] from the cam grooves of the Spindle [18] and Hammer [10] with a small flat-blade screwdriver. 8. Release the hand press and lift the Hammer [10] and Washer (S) [14] together to remove them from the Spindle [18]. 9. Then, remove Hammer Spring (J) [13].

1. Detach Ring Gear (E) [20] and O-ring (S-42) [21] from the Inner Cover [26]. 2. Use a small flat-blade screwdriver to remove Damper (A) [24]. NOTE: Be careful not to damage the O-ring (S-42) [21]. (Refer to diagram showing parts [20], [21], [22], [23], [24], [25], [26])

1. Peel off the silicone from the connectors of the DC-Speed Control Switch [36] with a flat-blade screwdriver. 2. Slowly push down the zip of the connector cable. 3. Slowly pull out the connector cable of the Wiring Ass’y [35].

1. When connecting the DC-Speed Control Switch [36], insert the connector of the connector cable into the connector of the DC-Speed Control Switch [36] securely until it is locked. 2. After inserting the connector cable into the connector, coat the entire circumference of the connector with silicone (Three Bond TB1211). Check that it is not covered with black oxide and plating is not peeled. NOTE: Do not carry or pull on the connector cable. 3. Push the ribbon cable and internal wire (A) in the guide groove on housing (A). 4. Insert the protrusion of the direction selector lever at the top of the DC-Speed Control Switch [36] into the hole on the Pushing Button [37]. Then mount it to housing (A). 5. Push internal wire (C) in between the rib for retaining the Hammer Case [6] and the rib in the switch chamber of housing (A) securely to prevent it from being caught between housings (A) and (B). Put internal wire (C) of the LED light between the ribs on housing (A). 6. Put the connector cable, ribbon cable, internal wire (B), and internal wire (C) between the two screw bosses.

1. Insert twenty-eight Steel Balls D3.175 [11] into the Hammer [10]. 2. Mount Washer (J) [12], Hammer Spring (J) [13], Washer (S) [14], and the Spindle [18] to the Hammer [10] in this order. 3. Align the top of the cam groove on the Spindle [18] with the steel ball guide groove on the Hammer [10]. Push down the tab at the tip of the Hammer [10] with a hand press or similar tool to compress Hammer Spring (J) [13] until it contacts the Spindle [18] and hold it there. 4. Insert one Steel Ball D5.556 [16] into the steel ball guide groove, then insert another Steel Ball D5.556 [16] into the steel ball guide groove on the other side. Check that the two Steel Balls D5.556 [16] are properly put in the cam groove. Then release the hand press. 5. Mount the hammer assembly onto the J-297 base for washer (S) (Code No. 317063). With a hand press, press down on the top of the Spindle [18] to compress Hammer Spring (J) [13]. In this condition, mount Stopper (C) [15] onto the spindle shaft facing its convex side upward. Then release the hand press. 6. Mount the Idle Gear Set (2 pcs.) [17] and two Needle Rollers [19] to the Spindle [18], and insert Washer (E) [22] to assemble the hammer assembly. 7. Mount Felt (B) [25] to the Inner Cover [26]. 8. Press-fit the Ball Bearing 6901VV [23] into the Inner Cover [26]. 9. Mount two Dampers (A) [24] to the Inner Cover [26]. 10. Mount the O-ring (S-42) [21] to Ring Gear (E) [20]. 11. Mount Ring Gear (E) [20] to the Inner Cover [26] aligning the retaining ribs of Ring Gear (E) [20] with the concave portions of Dampers (A) [24]. 12. Check that Washer (E) [22] is mounted to the Spindle [18]. Mount the hammer assembly to the Inner Cover [26] meshing the Idle Gear Set (2 pcs.) [17] with Ring Gear (E) [20] properly. 13. Mount Anvil [9] to the tip of the Spindle [18]. 14. Mount Washer (F) [7] to the Hammer Case [6]. 15. Then mount the Hammer Case [6]. NOTE: Check that the thick ribs on the Inner Cover [26] are positioned at 90° relative to the retaining tabs on the Hammer Case [6].

1. Before mounting the parts to housing (A), apply silicone rubber (Three Bond TB1211) to the specified shaded areas. 2. Mount the hammer assembly, Hammer Case [6], Inner Cover [26], and Wiring Ass’y [35] (including the DC-Speed Control Switch [36]) to housing (A). NOTE: * Fit the Hammer Case [6] in housing (A) so that the retaining tabs on the Hammer Case [6] are in contact with the retainer receptors on housing (A). * Put internal wire (C) of the LED light fitted in the groove on housing (A) between the retaining tab on the Hammer Case [6] and housing (A). * Check that the Hammer Case [6] is properly mounted to the housing. If the Hammer Case [6] is not fitted in the specified groove on the housing, or if the thick ribs on the Inner Cover [26] are not positioned at 90° relative to the retaining tabs on the Hammer Case [6], reassemble it. The equipment is structured so that the Hammer Case [6] will retain the parts axially when properly assembled. Therefore, check that the parts are properly mounted to the housing. 3. After coating shaded areas of housing (A) with silicone rubber (Three Bond TB1211), insert the Strap (Black) [40] into the boss (Model WH 18DE only). 4. Coat housing (B) with silicone rubber (Three Bond TB1211) at the similar location. 5. Apply grease (Nippeco SEP-3A) to the entire circumference of the Rear Bumper [38] and mount it to the housing. 6. Align housing (B) with housing (A) and tighten the eight Tapping Screws (W/Flange) D3 x 16 (Black) [32]. NOTE: * Use a cloth to wipe off silicone rubber adhered to the outer circumference of the housing. * Check that the stator of the Wiring Ass’y [35] is properly positioned between the retaining ribs on housings (A) and (B) without tilting before tightening the eight Tapping Screws (W/Flange) D3 x 16 (Black) [32]. Ensure the stator is mounted parallel to the housing, not slanted.

1. Press-fit the Rotor Pinion Ass’y [27] into Housing (A).(B) Set [29] from behind. NOTE: After mounting, check that the Rotor Pinion Ass’y [27] rotates smoothly. If the Rotor Pinion Ass’y [27] does not rotate smoothly, the gear is improperly engaged. In such a case, mount the Rotor Pinion Ass’y [27] properly. 2. Press-fit the Tail Cover [31] into Housing (A).(B) Set [29] and tighten the two Tapping Screws (W/Flange) D3 x 16 (Black) [32]. 3. After reassembly, run the motor at low speed to check that the Rotor Pinion Ass’y [27] rotates smoothly. NOTE: If the Rotor Pinion Ass’y [27] does not rotate smoothly, the gear is improperly engaged. In such a case, mount the Rotor Pinion Ass’y [27] properly. If the stator of the Wiring Ass’y [35] cannot be mounted to the housing properly, the core is out of position or there is a gap between housings (A) and (B) at the upper part of the motor. In such a case, mount the Wiring Ass’y [35] properly. Replace Housing (A).(B) Set [29] with new one if the ribs on housings (A) and (B) for holding the stator are deformed.

1. Mount the Front Cap [5] to the Hammer Case [6] so that the Front Cap [5] groove is positioned at the top of the product. 2. Insert the Hook [34] into the groove under the side of Housing (A).(B) Set [29], and then secure it in place with the Truss Hd. Screw M4 (Black) [33]. The Hook [34] can be installed on either right or left side of the unit.

1. Put the two Steel Balls D3.5 [8] into the Anvil [9]. 2. Mount the Guide Sleeve [4], Guide Spring [3], and Washer (D) [2] in this order. 3. Fit the Retaining Ring [1] in the groove of the Anvil [9] using the J-295 jigs (A) and (B) for retaining ring (Code No. 317060 and 317061). Press down to secure. NOTE: Do not reuse the Retaining Ring [1]. If reused, the Guide Sleeve [4] may come off. Be sure to replace the Retaining Ring [1] with a new one.

Please purchase the following silicone rubber as necessary:

Item	Registered part name	Net weight	Code No.
Three Bond 1211	Silicone rubber	100 g	306927

Apply specified amount of grease to the following portions:
MOLUB-ALLOY 777-1

• Convex portion (8 mm in dia.) on the Anvil [9]
• Sliding portion between the Anvil [9] and the needle bearing
• Two Steel Balls D5.556 [16]
• Cam groove, oiled groove, and raised faces on the Hammer [10]
• Cam groove and sliding portion of the Spindle [18]
• Hole (5 mm in dia.) in the Idle Gear Set (2 pcs.) [17]
• Entire circumference of two Needle Rollers [19]
• Twenty-eight Steel Balls D3.175 [11]
• Top surface of the claws on the Anvil [9] and sliding portion of Washer (F) [7]
• Inner circumference of the needle bearing of the Hammer Case [6]
• Contact surface between Washer (F) [7] and Hammer Case [6]

NIPPECO SEP-3A

• Two Steel Balls D3.5 [8]
• Entire circumference of two Rear Bumpers [38]

ATTOLUB MS NO. 2

• Toothed surfaces of the Rotor Pinion Ass’y [27] pinions, toothed surface of Ring Gear (E) [20], and toothed part of the Idle Gear Set (2 pcs.) [17].

Please purchase the following grease as necessary:

Item	Registered part name	Net weight	Code No.
MOLUB-ALLOY 777-1	Grease (Molub-Alloy No. 777-1) 75 g	75 g	375042
NIPPECO SEP-3A	Grease (SEP-3A) (100 g)	100 g	930035
	Grease (SEP-3A) (2.5 kg)	2.5 kg	930038
ATTOLUB MS NO. 2	Grease (Attolub MS No. 2) 500 g	500 g	309922

• Tapping Screws (W/Flange) D3 x 16 (Black) [32]: 1.3 ± 0.3 N•m {13 ± 3 kgf•cm}
• Truss Hd. Screw M4 (Black) [33]: 1.8 ± 0.4 N•m {18 ± 4 kgf•cm}

After reassembly, check the following:

1. Check that the equipment runs smoothly and starts, stops, changes speed, and changes direction securely.
2. Check that the rotating direction of the Anvil [9] matches that of the pushed side of the Pushing Button [37].
3. Check that the LED light keeps on lighting while the switch is pulled and goes off in about ten seconds when removing your finger from the switch.

2.7 ± 0.5 A (DC 19.8 V—equivalent to the voltage of a fully charged battery)

• Push the ribbon cable and internal wire (A) (2 pcs.) in the internal wire guide grooves.
• Push internal wire (B)/(D) into its groove near the battery terminal.
• Route internal wire (C) towards the LED light.
• Place the Capacitor PCB ass’y, Screw boss, Ribbon cable, Connector cable, and Screw boss connections as shown.
• Put connector cable, ribbon cable, internal wire (B), and internal wire (C) between the two screw bosses near the switch.

(Refer to Wiring Diagram and Connecting Diagram for visual layout)

Refer to the service manual for precautions on disassembly and reassembly of the charger Model UC 18YKSL, UC 18YSL3 or UC 18YFSL.