Published 4-20-2015, Control # 502-01 4-35
RT540E SERVICE MANUAL BOOM
1. Position the boom to horizontal before making
adjustments.
2. Slightly tighten all cables.
3. Fully retract the boom.
4. In the order listed here, tighten the 4/3/2 retract, the
2/3/4 extend, the 3/2/1 retract, and the 1/2/3 extend
cables to remove the excess slack from the cables.
5. In the order listed, torque the 4/3/2 retract, the 2/3/4
extend, the 3/2/1 retract, and the 1/2/3 extend cables to
the minimum torque values specified in Table 4-1.
To provide better access to adjust the 3/2/1 retract
cables, extend the boom approximately 300 mm (12 in),
then retract the boom approximately 150 mm (6 in) to
tension the cables correctly prior to torques being set.
Fully retract the boom before setting the torque on the
1/2/3 extend cables.
6. Fully cycle the boom.
7. Tighten the extend and retract cables as follows to
ensure that all boom sections fully extend and fully
retract simultaneously and that they do not drift out when
the hydraulic valve is in neutral.
a. If the 2
nd
stage is fully retracting late, loosen the
3/2/1 retract cables and tighten the 1/2/3 extend
cables. Extend and retract the boom a few feet. Re-
torque the 3/2/1 retract cables and the 1/2/3 extend
cables to verify that the minimum torque value is
achieved as specified in Table 4-1.
b. If the 3
rd
stage is fully retracting late, loosen the
4/3/2 retract cables, tighten the 2/3/4 extend cables,
then extend and retract the boom a few feet. Re-
torque the 4/3/2 retract cables and the 2/3/4 extend
cables to verify that the minimum torque value is
achieved as specified in Table 4-1.
8. Ensure that all extend and retract cables achieve the
minimum torque value as specified in Table 4-1.
9. Add jam nuts and tighten.
10. Coat all stud threads with Never Seize and install cable
protectors. All threaded cable ends must be equipped
with retainer nuts and jam nuts.
Table 4-1: Minimum Torque Values for Boom Cable Tensioning
Cables (Extend/Retract) Minimum Torque Values
4/3/2 retract 10.5 Nm (96 in-lb)
2/3/4 extend 40.5 Nm (360 in-lb)
3/2/1 retract 8 Nm (72 in-lb)
1/2/3 extend 16 Nm (144 in-lb)
Note: All above torque values shown are minimums and are calculated with the
use of a standard crow's foot attached to the torque wrench in a straight-ahead
position.
FIGURE 4-98
4-Section Boom Cable Positioning and
Adjustment Locations
Reference Only
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