Manitowoc National Crane 800D, Operator'S And Service Manual

Page: 157 / 256

National Crane
Published 5-27-2018 Control # 039-06 6-7
800D REPAIR
vertical movement of the telescope cylinder. Remove
bar.
15. Loosen capscrews retaining extend cable anchor to
back of the 3rd section. Total removal of the capscrews
will allow the cable anchor to be completely
disassembled, backing capscrews out approximately
0.50 in (12 mm) will allow the anchor assembly to slide
rearward out of the section as the telescope cylinder is
removed.
16. Support telescope cylinder with an appropriate lifting
device and pull the telescope cylinder out of the boom
while keeping the extend cables and anti-two-block wire
tensioned slightly by hand to minimize the possibility of
damage to the cables. Pull cylinder to within 3 ft (91 cm)
of complete removal from the boom sections.
17. Reach into the rear of the 3rd section and loosen and
remove the anti-two-block cable clamp on the extend
cable anchor. Pull the extend cable anchor out from its
retaining pocket on the bottom of the 3rd section. A
slight angle applied to the anchor as it’s being pulled to
the rear will permit easier removal through the 2nd
section.
18. Remove the telescope cylinder from the boom. Remove
extend cables. Place cylinder and cables in suitable
area to prevent possible damage.
19. Anti-two-block wire can be removed if necessary by
disassembly of the clamp arrangement at the sheave
case and pulling wire through boom.
20. Loosen and remove two capscrews, cable guide, wear
pad and spacer bar from the front top of the second
section.
21. Loosen and remove six capscrews attaching the bottom
pad plate to the second section. Slightly lift third section,
and remove pad plate.
22. Slide 3rd section out of 2nd section. Removal of side
pads is optional, as the side pads have adequate
clearance for boom disassembly. If removal of side pads
is required, tag all shims, pads and corresponding
locations for proper reassembly.
23. Loosen and remove all remaining capscrews and wear
pads from boom sections.
Boom Disassembly Alternative #2
The 800D boom design allows for removal of the telescope
cylinder from the rear of the boom without complete
disassembly of the boom sections. This procedure allows
quick access to the cylinder, retract cables, and various
internal boom components for service or replacement.
Do not, under any circumstances, work at an elevated
height without using proper fall protection as required
by local, state or federal regulations.
1. Remove hoist.
2. Gaining access through rear of boom, loosen and
remove capscrews retaining the keeper plates holding
the extend cable anchor in the rear of the 3rd section as
well as the anti-two-block wire clamp on the anchor
assembly. Loosen and remove two capscrews retaining
lock bar to telescope cylinder. Remove lock bar
3. Extend boom 24 in (61 cm). Loosen and remove the
nuts which secure the extend cables to the cable anchor
plate. Remove nut from anti- two-block spade bolt.
4. Drape extend cables and anti-two-block wire inside
boom, and slide cable anchor plate out of the side of the
hoist mount.
5. Loosen and remove two capscrews, lockwashers and
spacers which anchor the telescope cylinder rod butt
plate to the rear of the 1 st section.
6. Using appropriate lifting device, lift telescope cylinder up
and out of retaining slot on rear of 2nd section.
Retracting cylinder with an external hydraulic power
source during this step may be necessary.
7. Pull cylinder out through rear of boom assembly
approximately one-half the length of the cylinder.
Turning of the butt plate and rod 90 degrees may aid in
sliding cylinder through hoist mount area. Keep extend
cables tight to minimize the possibility of damage.
8. Lift telescope cylinder up until it contacts inside of boom
section. Remove anti-two-block wire clamp from extend
cable anchor. Remove anchor by pulling anchor and
cables out rear of boom. A slight angle applied to the
anchor as it’s being pulled to the rear will permit easier
removal.
9. Continue to pull telescope cylinder and cables out of
rear of boom. Remove extend cables and store in an
area to minimize the possibility of damage.
Additional Maintenance, Disassembled
Boom
1. Clean all boom sections and inspect for wear, dents,
bent or bowed boom sections, gouged metal, broken
welds or any abnormal conditions. Repair or replace as
required.
2. Inspect all sheaves for excessive groove wear or
abnormal rim wear. Replace as required.
3. Inspect all sheave bearings for excessive wear or cut
liner material. If installed bearing diameter is 0.015 in
(0.38 mm) larger than the pin diameter, bearing must be
replaced. Any cut or gouge which causes the bearing
liner to be distorted is cause for bearing replacement.
4. Clean and inspect all cable assemblies according to the
“Wire Rope Inspection Procedures” in this section. Pay
particular attention to any wire breakage within 6 ft (180
cm) of the end connections. Replace cable assemblies
Fo
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Reference
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