4
10
National Crane
Published 8-01-2017 Control # 287-11
4-7
NBT40 SERVICE MANUAL BOOM
MAINTENANCE
other steps apply to boom being removed from crane (See
“Boom Removal” on page 4-2).
1.
Extend and set the outriggers and SFO.
2.
Completely retract the boom and place it in a horizontal
position.
3.
Tag and disconnect the hydraulic lines to the telescope
cylinder. Cap all lines and openings.
4.
Loosen and remove two capscrews (11,8) and hardened
washers which anchor the 1st stage extend cylinder rod
(5) to the base of the 1st stage boom.
5.
Mark the location of the nuts and washer (9,8) which
secure the 1/2/3 extend cables (10) to the rear base of
the 1st stage boom base section (1). Remove nuts and
washers from 1/2/3 extend cables at 1st stage boom
base. Mark and tag cables while leaving the cable ends
draped inside the boom.
6.
Remove hardware (125,126) and access plate (124)
from top/rear of 1st section.
7.
Attach a sling or chain to the tip of the 2nd stage boom
and pull the 2nd stage boom (with the 3rd, and 4th
stages) out approximately one foot or until the access
openings on all boom sections align to the rear wear pad
assemblies for all boom sections. Tag and remove rear
wear pads from top of each boom section. Loosen
attaching hardware for the adjusting cam plates and all
rear top wear pads for all boom sections being removed.
8.
Remove and tag attaching hardware (28,40,61) on front
tip of lower 1st stage boom section. Loosen wear pad
adjustment hardware (104,97) wear pads (63) and back
plates (22,70).
9.
Remove and tag upper plate (16) and shim (101) and
hardware (23,21,56) from tip of 1st stage boom.
10.
Remove and tag two upper side wear pad assemblies
(163) with keeper side wear pad (164,160) and
hardware (162,161) from tip of 1st stage boom.
11.
Loosen cable adjusting nuts (113,12) on lower front 3/2/
1 retract cables (19). Remove four capscrews (27) which
retain the 3/2/1 retract cable anchors plates (115) to the
bottom tip of the 1st stage boom. Pull the retract cable
anchors out and keep retract cables taunt while pulling
2nd (with 3rd, and 4th) stage out of 1st stage. Partially
pull 2nd stage boom from boom assembly until front tip
of boom can be raised enough to remove and tag wear
pads (165,166) and hardware (20,49) from bottom tip of
1st stage boom. Support the base end of the 2nd stage
as it exits the 1st stage boom.
12.
Place 2nd stage (with 3rd, and 4th) on a suitable
horizontal surface.
NOTE:
Use caution not to pinch or crush retract cables
while lifting or supporting 2nd stage boom.
13.
Tag and remove rear wear pads and shims from base of
2nd stage boom if replacing.
14.
Remove capscrew (66) and retract cable guide roller
(32) from each side of the bottom base of the 2nd stage
boom.
15.
Remove the two square head setscrews (117) which
retain 3/4 retract sheave pin (38). Pull the retract sheave
pin with retract sheaves (114) and bearing (35) spacers
(36) and snap ring (37) assembled back out of its slot at
the base of the 2nd stage boom. Smooth out any burrs
which may be present on flat ends of pin to eliminate
sheave bearing damage when sheaves are removed
from pin.
16.
Remove two capscrews (107), retract cable keeper
bracket (108) and cable anchor assembly (51) from
lower base at rear of 3rd stage boom. Store 3/2/1 retract
cables (19), which are now free, in an area where they
will not be damaged during further boom disassembly.
17.
Mark the location of the nuts which secure the 2/3/4
extend cables (29) to the base of 2nd stage boom.
Remove six large nuts (31), spacer (152) and the 2/3/4
extend cable anchor assembly (30) from the top/base of
the 2nd stage boom.
18.
Remove two socket head screws (118) and two socket
flathead screws (27) which retain the wear pad (39) to 2/
3/4 extend cable anchor (30) attached to the top/base of
the 2nd stage boom.
19.
Attach a sling or chain to the tip of the 3rd stage boom
and pull 3rd stage boom (with the 4th stage) out
approximately one foot. Remove and tag two lower side
wear pads (15) with shims (14,13) and two upper side
wear pads (164,163,160,162,161) from front tip of 2nd
stage boom. Remove and tag two top inner steel pad
(58) and shim (102) from tip of the 2nd stage section.
20.
Remove and tag cable retainer assembly and hardware
(54,33,56,21,55,57) located top front tip of the 2nd stage
boom.
21.
Slide the 1/2/3 extend cable sheave case assembly
(44,45,46,47,43) out from the top/front tip of the 2nd
stage boom and allow the sheave case assembly and
cables (10) to rest on the top of the 3rd stage boom.
22.
Loosen adjustment nuts (12,113) from retract cable (53)
and remove four capscrews (27) which retain the 4/3/2
retract cable anchor plate assembly (26) to the bottom
tip of the 2nd stage boom.
23.
Raise tip of boom and remove wear pads (17) from
between bottom tip of the 2nd stage and 3rd stage
boom. Pull the retract cable anchors out and keep the
retract cables taunt while pulling the 3rd, and 4th stage
booms out of the 2nd stage boom.
Reference Only
Содержание National Crane NBT40 Series
Страница 1: ...Service Manual National Crane NBT40 Series R e f e r e n c e O n l y ...
Страница 2: ...R e f e r e n c e O n l y ...
Страница 122: ...BOOM MAINTENANCE NBT40 SERVICE MANUAL 4 48 Published 8 01 2017 Control 287 11 THIS PAGE BLANK R e f e r e n c e O n l y ...
Страница 136: ...HOIST NBT40 SERVICE MANUAL 5 14 Published 8 01 2017 Control 287 11 THIS PAGE BLANK R e f e r e n c e O n l y ...
Страница 162: ...OUTRIGGERS NBT40 SERVICE MANUAL 7 10 Published 8 01 2017 Control 287 11 THIS PAGE BLANK R e f e r e n c e O n l y ...
Страница 214: ...CRANE INSTALLATION NBT40 SERVICE MANUAL 9 36 Published 8 01 2017 Control 287 11 7488 4 7488 6 R e f e r e n c e O n l y ...
Страница 216: ...SCHEMATICS NBT40 SERVICE MANUAL 10 2 THIS PAGE BLANK R e f e r e n c e O n l y ...
Страница 218: ...NBT40 SERVICE MANUAL APL 2 THIS PAGE BLANK R e f e r e n c e O n l y ...
Страница 219: ...R e f e r e n c e O n l y ...
Страница 220: ...R e f e r e n c e O n l y ...