P 4/ 12
Repair
[3]DISASSEMBLY/ASSEMBLY
[3]
DISASSEMBLING
After removing Drill chuck (Re: Figs. 1, 2, 3 and 4), disassemble Motor section and Gear assembly. (Figs. 8 and 9)
Fig. 8
1.Remove two 3x16 Tapping screws and Rear cover. And remove four 4x18 Tapping screws.
Rear cover
3x16 Tapping 
screw (2 pcs.) 4x18 Tapping
screw (4 pcs.)
2.Remove Housing R, unscrewing seven 3x16 Tapping screws.
3x16 Tapping screw (7 pcs.)
3.Pull out Heat sink section, and remove Gear assembly together with Motor section and Speed change lever.
4.Remove Speed change lever and Motor section from Gear assembly.
Motor section | Speed change lever |
Gear assembly
Heat sink section
Motor section
Speed change lever assembly
5.Push Speed change lever assembly toward Motor side until it stops to have space between the pin on the lever of Gear assembly and rear Compression spring 4.
Motor side | Drill chuck side |
rear Compression spring 4
6.Lifting up Motor side of Speed change lever assembly, pull it toward the direction designated with arrow.
Drill chuck side Motor side 
Pin on 
the lever of 
Gear assembly
Space between rear Compression spring 4 and the pin on the lever of Gear assembly.
front Compression spring 4 compressed by the lever of Gear assembly
Fig. 9
5.Shift the tail of Torsion spring from top of Carbon brush to the Notch of Brush holder. Carbon brush gets free from the pressure of Torsion spring.
Carbon brush
6. From Armature, pull off Brush holder complete and Yoke unit.
Yoke unit
Armature
Torsion spring | Brush holder complete |
Note: Pay attention not to pinch your finger between Yoke unit and Armature when removing. 
Do not scratch the copper wires of Armature. Yoke unit draws Armature by its considerable strong magnet force.