Hitachi DH 40MEY Service Manual page 8

Reassembly can be accomplished by reversing the disassembly procedure. However, special attention
should be given to the following items.
1. Reassembly of the hammering mechanism and low vibration mechanism
(1) First gear and crank shaft
Press-fit Oil Seal (B) [88] to the Crank
Case [89]. Mount the O-ring [86].
Press-fit the Ball Bearing 6203DD [87].
Use a retaining ring puller to mount the
Retaining Ring [85].
Press-fit the Crank Shaft [83] to the Ball
Bearing 6203DD [87].
Insert the Feather Key [84] into the
Crank Shaft [83] groove. Support the
plane of the Crank Shaft [83] with an
adequate steel rod and use an adequate
tool to press-fit the First Gear [128].
Prior to press-fitting, make sure the
Feather Key [84] matches the key
groove of the First Gear [128].
(2) Piston
Insert the Connecting Rod Ass'y [39] into the Piston [38], and then press-fit the Piston Pin [37] from
the D8 hole (marked " 2") of the Piston [38]. Be careful not to let the Piston Pin [37] project from the
outer diameter of the Piston [38]. Mount the O-ring [36] on the Piston [38] to make the piston ass'y.
Next, turn the Crank Shaft [83] to the position shown below, and then mount the piston ass'y to the
Crank Shaft [83] from the Cylinder Case [13] side of the Crank Case [89].
The piston ass'y can be assembled even when the Bevel Gear [34] and Slip Clutch Ass'y [114] are
mounted to the Crank Case [89].
Fig. 9
[37]
[36] [38]
Reassembly
" 2" mark
[39]
Fig. 8
[128]
[89]
[88]
[86] [87]
[89]
-7-
Adequate tool
[84]
[83]
[85]
Adequate
steel rod
[83]