Manitowoc National Crane NBT40 Series, Service Manual

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BOOM MAINTENANCE NBT40 SERVICE MANUAL
4-22
Published 8-01-2017 Control # 287-11
sheave pin with retract sheaves (148) 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.
15. Remove two capscrews (145), retract cable keeper
bracket (144) 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.
16. 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), spacers (87) and the 2/3/4
extend cable anchor assembly (30) from the top/base of
the 2nd stage boom.
17. Remove two socket head screws (155) 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.
18. Remove two allen head shoulder bolts (11) with
flatwashers (8) from the extend cylinder (6) anchor
brackets as part of the center base at rear of the 2nd
stage boom section.
19. Attach a sling or chain to the tip of the 3rd stage boom
and pull 3rd stage boom (with the 4th and 5th stages) out
approximately one foot. Remove and tag two lower side
wear pads (15) with shims (14,13) and two upper side
wear pads (178,179,180,162,161) from front tip of 2nd
stage boom. Remove and tag two top inner steel pad
(58) and shim (137) from tip of the 2nd stage section.
20. Remove and tag cable retainer assembly and hardware
(54,33,56,21,55,117,57) 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 (12,151) 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, 4th and 5th
stage booms out of the 2nd stage boom.
24. Place the 3rd, 4th and 5th stage booms on a suitable
horizontal surface.
NOTE: Use caution not to pinch or crush retract cables
while lifting or supporting 3rd stage boom.
25. Tag and remove wear pads and shims from base of 3rd
stage boom if replacing.
26. Remove the 1/2/3 extend cable (10) from top of 3rd
stage boom. Slide the top center rear sheave (71)
toward the rear of boom and remove. Pull the cable loop
forward and remove from sheave keeper. Cable is now
free at base of boom. Push the two sheaves at the front
tip of the 2nd stage boom forward and remove them
from the 1/2/3 extend cable sheave case assembly (44)
and sheaves (46) previously removed and stored at the
tip of the 3rd stage boom. The cable loops may now be
pulled back out of the sheave case and the 1/2/3 extend
cable is free. The cable loops may now be pulled back
out of the sheave case and the 1/2/3 extend cable is
free. Smooth out any burrs which may be present on the
flat ends of the pins to eliminate sheave bearing damage
and if necessary to remove pins from tip sheaves (47).
27. Loosen and remove two capscrews (27) retaining wear
pad (72) to top base of 3rd stage boom. Loosen and
remove two capscrews (48) lockwashers (49) and
keepers (50) which anchor the extend cylinder (6) at the
center base of the 3rd stage boom. Attach a sling to the
base of the extend cylinder and pull the extend cylinder
out of the 3rd stage boom approximately one foot
keeping 2/3/4 extend cables taunt. Raise and support
extend cylinder approximately five inches using a block
(wood).
NOTE: Avoid damage to retract cable roller (65) when
lifting cylinder.
28. Remove capscrew (74) and retract cable roller (65) from
each side of the bottom base of the 3rd stage boom. Pull
the retract sheave pin (191) with retract sheaves
assemblies (34,35,36,37) back out of its slot at the
bottom base of the 3rd stage boom. Disconnect
lubrication tubes (192,193) between shaft and retract
sheaves if equipped. Smooth out any burrs which may
be present on flat ends of pin to eliminate sheave
bearing damage if sheaves are removed from pin. Stow
cable (53) out of way to avoid damage.
29. Push the 4/3/2 retract anchor (82) forward out of its slot
in the bottom base of the 4th stage boom and remove
from 4th stage boom with wear pad (81) attached.
Remove 4/3/2 retract cables (53) from 4/3/2 retract
anchor (82) and store in an area where they will not be
damaged during further boom disassembly.
30. Mark the location of the nuts which secure the 5/4/3
retract cables (77) to the tip of the 3rd stage boom and
loosen nuts (12,151) and remove plate (107) and
capscrew (32) to the end of cable thread.
31. Remove capscrew (85) and retract cable roller (84) from
each side of the bottom base of the 4th stage boom.
32. Remove 5/4/3 retract cable anchor capscrew (106) from
the inside base of the 5th section. Remove 5/4/3 retract
Reference Only