Reassembly - Hitachi DH 40FR Technical Data And Service Manual

9-2. Reassembly

Reassembly can be accomplished by following the disassembly procedure in reverse. However, special attention
should be given to the following items.
(1) Reassembly of the first gear and the crank shaft
Press-fit Oil Seal (B) [39] into the Cylinder Crank Case [40] and mount O-ring (S-40) [38]. Press-fit the Ball
Bearing 6203DDCMPS2L [37]. Mount the Retaining Ring for D40 Hole [36] using a retaining ring puller.
Press-fit the Crank Shaft [34] into the Ball Bearing 6203DDCMPS2L [37]. Put the Feather Key 3 x 3 x 8 [35]
in the groove of the Crank Shaft [34] and press-fit the First Gear [55] with a suitable tool while holding the flat
portion of the Crank Shaft [34] with a steel bar. Before press-fitting, make sure that the Feather Key 3 x 3 x 8
[35] fits in the key groove of the First Gear [55] (Fig. 14).
Cylinder Crank Case [40]
(2) Reassembly of the piston
Insert the Piston Pin [24] into the 8-mm dia. hole (marked side) of the Piston [23] and the Connecting Rod [25]
then press-fit it. Mount the O-ring [21] to the Piston [23]. Be careful not to protrude the Piston Pin [24] from
the outside diameter of the Piston [23]. Move the crank pin of the Crank Shaft [34] to the bottom dead center
and mount the piston assembly to the Crank Shaft [34] from the front cover side of the Cylinder Crank Case
[40]. Mount the Retaining Ring for D10 Shaft [33] using a retaining ring puller (Fig. 15).
Piston Pin [24]
O-ring [21]
Piston [23]
First Gear [55]
Cylinder Crank Case [40]
Mark
Connecting Rod [25]
Steel bar
Fig. 14
Retaining Ring for
D10 Shaft [33]
Fig. 15
--- 17 ---
Suitable tool
Feather Key 3 x 3 x 8
[35]
Oil Seal (B) [39]
O-ring (S-40) [38]
Ball Bearing
6203DDCMPS2L [37]
Retaining Ring for
D40 Hole [36]
Crank Shaft [34]
Crank pin
Crank Shaft [34]