4
10
National Crane
Published 8-01-2017 Control # 287-11
4-25
NBT40 SERVICE MANUAL BOOM
MAINTENANCE
boom and install the button end of the 3/4/5 extend
cables (96) into outer side anchor plates at the base
of the 5th stage boom and pull taunt.
5th and 4th Section Boom
1.
Install 5th stage boom (5) into 4th stage boom (4)
approximately five feet. Figure 4-7.
NOTE:
Take care not to damage 3/4/5 extend cables (96).
2.
Raise 5th stage boom against the top of 4th stage boom
and install wear pads (100) securing with capscrews
(101) on the bottom tip of the 4th stage boom (4) and
lube.
3.
Lower the 5th stage boom (5) onto the wear pads in the
4th stage boom.
4.
Install 3/4/5 extend sheave assembly (98) inside tip of
4th stage boom (4).
a.
Install bearing assembly (99) in sheave (98).
b.
Install wear plugs (97) into (fourteen) holes per
sheave (98).
c.
Loop 3/4/5 extend cables (96) around 3/4/5 extend
sheaves (98) and install sheaves into the 4th stage
boom (4).
NOTE:
Install cables in their natural untwisted condition.
Do not twist cables. Twisting of cables will result in
damage or failure of cable.
d.
Install 3/4/5 extend sheave pins (189) and plugs
(97) into the recessed holes in the sides of the tip of
the 4th stage boom.
e.
Install retaining capscrews (40) into 3/4/5 extend
sheave pins (189) and torque (See “Fasteners And
Torque Values” on page 1-7).
f.
Install grease fittings (95) into 3/4/5 extend sheave
pins (189) and lube.
5.
Install side wear pads (89), shims (90,91) with
capscrews (27) to inside tip of the 4th stage boom (4).
6.
Install cable guide assembly (105) on the top of 4th
stage boom (4).
a.
Insert upper steel wear pad (102) with shims (139)
between 4th stage boom (4) and top of the 5th stage
boom (5).
b.
Install capscrew (59) in rear holes only.
c.
Install wear pad (104) and cable guide (105) to
outside tip of 4th stage boom (4). Install related
hardware (146,21,56) to secure from the top front of
the 4th stage boom.
NOTE:
Shim according to calibration instructions in this
section or as pads were originally removed and
tagged.
d.
Push the 5th stage boom completely into the 4th
stage boom while keeping 3/4/5 extend cables (96)
taunt.
e.
Scribe a mark in the tip of the 5th stage boom in
front of side wear pads on the 4th stage boom, for
retract sequencing.
7.
Install 3/4/5 extend cable retaining pads (88) with the
flanged lip facing upward/toward the inside of the base
of the 4th stage boom in order to support the cable (96).
8.
Install the upper capscrew (108), washer (56), nut (133)
only and swing the retaining pad (88) and position the 3/
4/5 extend cables (96) between the opening of cable
retaining pad and the side plate and with the threaded
end of the 3/4/5 extend cable routed beyond the base of
4th stage boom. Swing the retaining pad (88) into place
and install the lower capscrew (108), washer (56), nut
(133) and tighten both capscrews. (See “Fasteners And
Torque Values” on page 1-7).
9.
Push threaded end of 5/4/3 retract cable (77) through
sheave opening in the bottom base end of the 4th stage
boom and pull 5/4/3 retract cables threaded ends
towards tip of boom.
10.
Install button end of the 5/4/3 retract cable (77) into
cable anchor on the inside base end of the 5th stage
boom (5).
11.
Install cable retaining screw (106) to secure cable.
12.
Temporarily install the retract-2/3/4 extend pin (78)
assembly with sheave (79) at the bottom base of the 5th
stage boom to aid in positioning cables (77) during
assembly of next section.
13.
Extend the 5th section approximately 1 foot to install the
top wear pads through the opening on top of boom at
the rear of the 4th section.
14.
Install two top wear pad mounting plates (152), top wear
pads (173), adjustment cam plate (200), capscrews
(197) and flatwashers (196).
3/4/5 EXTEND CABLE
4TH STAGE BOOM
CABLE THREAD
CABLE BUTTON
CABLE ANCHOR
5TH STAGE BOOM
FIGURE 4-7
Reference Only
Summary of Contents for National Crane NBT40 Series
Page 1: ...Service Manual National Crane NBT40 Series R e f e r e n c e O n l y ...
Page 2: ...R e f e r e n c e O n l y ...
Page 216: ...SCHEMATICS NBT40 SERVICE MANUAL 10 2 THIS PAGE BLANK R e f e r e n c e O n l y ...
Page 218: ...NBT40 SERVICE MANUAL APL 2 THIS PAGE BLANK R e f e r e n c e O n l y ...
Page 219: ...R e f e r e n c e O n l y ...
Page 220: ...R e f e r e n c e O n l y ...