Hitachi NR90GC - 3-1/2" Gas Powered Clipped Head Framing Nailer Technical Data And Service Manual page 66

(b) Reassembly
Reassembly procedures should be followed in the reverse order. Note the following points.
Be careful of the split direction of the Roll Pin D2.5 x 10 [99] when mounting the Trigger [98] and Internal Wire
(A) [86]. Do not damage the plunger of the switch (Fig. 55).
Perform wiring of the Controller [101] and Internal Wire (A) [86] as shown in Fig. 56. Position the other parts
as shown in Fig. 56. Do not apply tension to the high-voltage cable of the Controller [101] and the connector
of Internal Wire (A) [86] (Fig. 56).
Mount the Wiring Cover [103] to Handle (B) [84] then hang the Chamber Lock Bar [100] on the ring of the
Lock Bar Spring [102]. Hang the magazine plate on the claw of Handle (B) [84] (3 places) (Fig. 58).
Be careful of the mounting direction of the Tension Plate [113] (Fig. 59).
Roll Pin D2.5 x 10 [99]
Internal Wire (A) [86]
Fig. 55
--- 63 ---
Split
Plunger
Trigger [98]