Manitowoc National Crane NBT40 Series - Five Section Cable Tensioning

BOOM MAINTENANCE NBT40 SERVICE MANUAL
4-36 Published 8-01-2017 Control # 287-11
Five Section Cable Tensioning
After boom reassembly or from time to time if interior
proportioning cables appear loose, cable tensioning may be
required.
Tensioning Setup Procedure
Tensioning must be done with the boom in the horizontal
position. reference Figure 4-10
When tightening/loosening the first (adjustment) nuts on
cables, secure cable using the wrench flats at the front of the
cable ends to prevent cable twist. Excess twisting of cables
can cause premature failure.
Ensure boom is completely assembled and fully retracted.
1. Mark the front of each section with a chalk line as
indicated in Figure 4-10.
2. Extend and retract boom several times to establish
working state of cables.
3. Extend boom so scribed lines are exposed by
approximately 12 inches.
4. Measure the extension gaps between each boom
section and scribed line and note values.
5. Retract boom so that the scribed lines are exposed by
approximately 6 inches.
6. Measure the retraction gaps between each boom
section and scribed line and note values.
7. Extend and retract the boom a few times and then
repeat measuring the extension gaps.
8. Adjust all corresponding cables according to following
instructions.
Cable Tightening Sequence
NOTE: When adjusting cable, hold the cable end and turn
the nut. Do not turn the cable. Turning the cable
while adjusting may result in damage or failure of
the cable.
176 Hex Head Capscrew M6x70
177 Flatwasher 6
178 Keeper Side Wear Pad
179 Side Wear Pad
180 Keeper Side Wear Pad
181 Socket Flat Head Capscrew M10x16 10.9
183 90 Deg Elbow
184 Wear Pad, Left
185 Wear Pad, Right
186 Socket Flat Head Capscrew 1/2-13uncx1
187 Wear Pad
188 Fitting
191 Pin
192 Tube L.h., 3rd Section
193 Tube R.h., 3rd Section
194 Tube L.h., 4th Section
195 Tube R.h., 4th Section
196 Flatwasher 10
197 Hex Head Capscrew M10x12 -10.9
198 Hex Head Capscrew M10x14 -10.9
199 Hex Head Capscrew M10x16 -10.9
200 Cam Plate Rear Wear Pad
201 Pin
202 Roller
203 Retaining Ring (1.25 Dia)
204 Cable Protector
300 Boom Wear Pad Kit
Five Section Boom
Item Description
8860-5
8860-6
FIGURE 4-10
Reference Only