National Crane 600H, Service Manual

Page: 88 / 232

BOOM 600H SERVICE MANUAL
4-14
08-19-2022 Control # 092-13
potential for damage. Assemble retract sheaves and
retract sheave pins in rear of 3
rd
section. Coat surfaces
of bearings and keeper plates with grease before
assembly.
11. Place retract cables anchored to 4
th
over the top of the
retract sheaves on the 3
rd
. Install keeper capscrew
above sheave to hold retract cables in place.
12. Reeve cables over retract sheave and install keeper/
wear pad to bottom rear of 3
rd
section. This pad acts as
a side pad, bottom pad, and a cable retainer. Loctite rear
wear pad hardware on bottom of 3
rd
section with Loctite
243 blue. Loctite all wear pad mounting capscrews.
13. Loop the 1/2/3 extend cable in half and place it on the
top of the 3
rd
section, with the loop end towards the
sheave case end and the threaded and button end
towards the rear of the section.
14. Install clamp plate and capscrews with the button end of
the cable installed in the anchor slot on the rear top of
the 3
rd
section.
15. Place sheave pin and sheave for the 1/2/3 extend cable
in position on the sheave case end of the boom, inside
the loop of cable
16. Install 3
rd
and 4
th
section boom assembly into 2
nd
section. Slide together approximately 5 ft (150 cm). Use
caution as retract cables and upper extend cable
attached to the 4th-3
rd
section assembly slide into the
2
nd
section to prevent damage or crossing of cables.
17. Assemble bottom front wear pads for 2
nd
section and
Teflon plugs. Attach pads to pad plate.
18. Using appropriate lifting device, lift 3
rd
and 4
th
section
assembly to allow for wear pad/pad plate installation in
front of 2
nd
. Install wear pad/pad plate assembly. Slide
sections together within 12 in (30 cm) of full retraction.
19. Install cable guide and spacer to top of 2
nd
section
20. install front side wear pads with appropriate shims
between 3
rd
and 2
nd
sections. If boom has been
disassembled, and no sections have been replaced, use
same shim quantity and location as was previously
used. If locations are in question, refer to shim
calibration section in this book. Slide sections fully
together
21. Assemble top rear wear pads to the top of the 3
rd
boom
section. Wear pads can be inserted from the hoist mount
end of the boom, and the cam plates dropped through
the holes in the aligned boom top plates.
The wear pad on each side at the top/rear of the boom
can be adjusted over a range of 3/16in (4.8 mm) by
rotating, end for end, the wear pad and plate or the wear
pads and plate independently. This is possible because
the holes in these parts are offset from the center. The
holes are 0.06 in (1.5 mm) off center in the plate and
0.03 in (0.8 mm) off center in the wear pad. Various
combinations of rotation of these parts allow the
adjustment.
a. Adjust pads until they are within 0.03” (.8mm) off
center in the wear pad. Various combinations of
rotation of these parts allows the adjustment.
b. Torque retainer capscrews, refer to Fasteners and
Torque Values pg 1-7. Failure to properly torque
capscrews will cause loss of preload and cause
excessive side clearance between sections.
22. Position sheave and sheave pin located in cable loop on
top of 3
rd
to allow capscrew installation, through top
plate of 2
nd
. Install capscrews and torque to
specification, clamping sheave pin and sheave to the
bottom of the 2
nd
section top plate.
23. Assemble retract sheaves, retract sheave pins and
cable keeper plates in rear of 2
nd
section. Coat surfaces
of bearings with grease before assembly.
24. Place retract cables anchored to 3
rd
over top of retract
sheaves attached to rear of 2
nd
. Install keeper capscrew
above sheave to hold retract cables in place.
25. Reeve cables over retract sheave and install keeper/
wear pad to bottom rear of 2
nd
section. This pad acts as
a side pad, bottom pad, and a cable retainer.
26. Assemble exterior extend cylinder components. Install
and center sheave pin and anti-two block sheave into
sheave case end of extend cylinder. Install bearings into
extend cable sheaves. Coat surface of bearings with
grease and assemble extend sheaves on sheave pin.
27. Wrap approximately 10 ft (300 cm) of each 5/8 in (15.88
mm) diameter 2/3/4 extend cable around extend
sheaves and install 4
th
section extend cable anchor
around cables at button end. Do not tighten capscrews
clamping anchor together completely. These capscrews
if tightened completely will not allow cable anchor to
install into 4
th
section.
28. Install wear pad over extend cylinder sheave side plates.
This serves as a wear pad to keep the end of the extend
cylinder centered in the boom, as well as an extend
cable retainer.
29. Slide extend cylinder/extend cables into 2
nd
/3
rd
/4
th
boom assembly enough to assemble extend cable
anchor into bottom rear of 4
th
section. Be aware of
extend cable location when inserting cylinder into boom
sections, inadvertent crushing or other damage to
cables will warrant replacement.
30. Tighten capscrews clamping extend cable anchor
together. This will also lock anchor in place in the anchor
cutouts in the 4
th
section.
REFERENCE ONLY