National Crane Published 10-30-2014 Control # 040-09 5-35
1400H OPERATOR AND SERVICE MANUAL SERVICE
with appropriate hardware to the inside top of the 1st.
Shim according to calibration instructions, or as pads
were originally removed and tagged.
51. Slide the 2nd-3rd-4th-5th and cylinder assembly into the
1st section until the extend cylinder butt plate contacts
the back plate of the hoist mount. Use caution as the
holding valve nears the hoist mount back plate, the
holding valve to back plate clearance requires the butt
plate to be level, with the holding valve down. Use
caution as the 3/2/1 retract cable threaded ends get
close to the grooves in the lower front pad plate, adjust
as necessary to allow proper placement.
52. Install proper hardware retaining extend cylinder butt
plate to the 1st section hoist mount.
53. Assemble top rear wear pads with the cam plates to the
top of the 2nd section. See step #11 for pad installation
detail.
54. Install cable guides, angle pendulum, hoist and anti-two
block system, see anti-two block system description and
installation instructions.
Top/Rear Side Pad Adjustment
With the boom fully retracted, locate the inner boom
section horizontally in the outer boom section it is riding in. A
pry bar can be used to manipulate the side to side position of
the section, however it is often difficult to pry the very most
inner sections over. To assist in this process a keyhole slot is
provided in the side plate of the first section to allow access
to the 4th and 5th sections (on the five section boom
configuration only). Insert the head of a capscrew into this
slot and pull it into the slot opening in the boom section side
plate you want to move. Install a large washer and nut on the
capscrew, creating a clamp between the 1st section and the
section requiring adjustment. Tighten capscrew to pull inner
section over to a position that centers it within the section it is
riding in.
Extended boom straightness is critical for proper boom
operation, The extended boom straightness required is a
deviation of 0.50 in (13 mm) or less from the theoretical
centerline of the boom. A string line from the center of the
hoist to the middle of the sheave case on the last section will
provide a theoretical center line. The top rear pads should be
adjusted accordingly to provide proper clearances to achieve
a straight extended boom.
Needs adjustment. The capscrews can not be installed
and there is a gap between the wear pad and side plate of
the larger boom section.
Assemble the top/rear wear pads and plates. The top/
rear wear pads on this boom are adjustable to account for
lateral tolerances that occur during the manufacturing
process of the boom sections. The wear pad on each side
at the top/rear of the boom can be adjusted over a range of
3/16 in (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 (1,6 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.
Once the boom section has been centered within the
section it is riding in, the wear pad and plate combinations
can be inserted into the space between the boom sections
and aligned over the holes in the sections. If the holes in the
plate are not centered over the holes in the sections, the
wear pads and plates have to be removed and adjusted
either towards or away from the side plate of the next larger
section until the holes will align. When properly aligned the
wear pad should be tight against the side plate of the outer
boom section and the extended boom should be straight to
previously mentioned specifications.
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