Precautions In Disassembly And Reassembly; Disassembly - Hitachi FDV 20VB Technical Data And Service Manual

8. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY

Please follow the precautions below for disassembly and reassembly procedures.
The [Bold] numbers in the descriptions below correspond to the item numbers in the Parts List and exploded
assembly diagram.

8-1. Disassembly

8-1-1. Removal of the Drill Chuck
(1) For keyless chuck
The Drill Chuck [3] (keyless chuck) is fixed to the Spindle and Gear Set [4] with a UNF 1/2" - 20 right-hand
thread and Flat Hd.Screw (A) (Left Hand) M6 x 25 [1]. First, open the jaws of the keyless chuck fully. Insert a
14 mm wrench into the wrench mounting portion of the Spindle and Gear Set [4] and turn the Flat Hd. Screw
(A) (Left Hand) M6 x 25 [1] clockwise to remove it. Then, fit the hexagonal bar wrench for M10 into the
keyless chuck and turn it counterclockwise to loosen and remove the keyless chuck.
(2) For conventional chuck (with chuck wrench)
The Drill Chuck [3] is fixed to the Spindle and Gear Set [4] with a UNF 1/2" - 20 right-hand thread and Flat Hd.
Screw (A) (Left Hand) M6 x 25 [1]. As shown in the figure below, fit a J-78 ring ass'y (special repair tools,
Code No. 970817 and 970818 are recommended) onto the drill chuck body, and secure it in a vise. At this
time, ensure that the pin of the ring ass'y is properly inserted into the chuck wrench mounting hole of the
chuck. Open the jaws of the Drill Chuck [3] fully and turn Flat Hd. Screw (A) (Left Hand) M6 x 25 [1] clockwise
with a flat-blade screwdriver to remove it. Then, fit a 14 mm wrench to the flat surfaces on the spindle, and
rotate it counterclockwise to loosen and remove the drill chuck.
When mounting portion of
Spindle and Gear Set [4]
14 mm wrench
Drill Chuck [3]
Main body
J-78 ring ass'y
Vise
Hexagonal bar wrench for M10
Vise
14 mm wrench
When mounting portion of Spindle and Gear Set [4]
Drill Chuck [3]
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