Manitowoc Grove RT770E, Service Maintenance Manual

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BOOM RT770E SERVICE MANUAL
4-34 Published 11/26/2014, Control # 447-05
1. In running ropes, six randomly distributed broken wires
in one lay or three broken wires in one strand in one lay.
2. Kinking, crushing, bird caging, or any other damage
resulting in distortion of the rope structure.
3. Evidence of any heat damage from any cause.
4. Reductions from nominal diameter of more than 5%.
5. In standing ropes, more than two broken wires in one lay
in sections beyond end connections or more than one
broken wire at an end connection.
Adjustment
Adjustment of the interior proportioning cables (extend and
retract cables) is necessary after assembly of the boom or
when interior proportioning cables appear loose.
Refer to the following procedures and Figure 4-59 when
adjusting the extend and retract cables.
NOTE: Ensure the boom is in the horizontal position when
tensioning the cables.
NOTE: Ensure all cables are torqued to the minimum
torque values specified in Table 4-1 to ensure
adequate cable tensions.
NOTE: Assure that all threaded studs allow the nut to
thread on and off by hand.
1. Extend and set the outriggers, ensuring the crane is
level.
2. Ensure the boom is over the front and at a horizontal
position (boom angle elevation 0°).
3. Slightly tighten all cables.
4. Fully retract the boom.
5. Tighten the Tele 4 retract, Tele 4 extend, Tele 3 retract,
and Tele 3 extend cables (in order listed) to remove
excess slack from the cables.
6. Torque the Tele 4 retract, Tele 4 extend, Tele 3 retract,
and Tele 3 extend cables (in order listed) to the minimum
torque values as specified in Table 4-1.
7. Fully extend and retract the boom.
8. Ensure Tele 3 and 4 bottom out on their respective stop
blocks 3mm to 4mm prior to Tele 2 bottoming out on Tele
1.
Tighten the extend and retract cables as necessary to
insure that all sections bottom out properly and that they
do not drift out when the hydraulic valve is in neutral.
To attain these conditions, perform the following
procedures.
a. If Tele 3 bottoms out prior to Tele 4, loosen Tele 3
extend and retract cables. Extend and retract the
boom a few feet. Tighten Tele 3 extend cables.
Extend the boom a few feet and tighten Tele 3
retract cables. Retract the boom fully. Repeat until
the section bottoms out properly. Re-torque the Tele
3 retract cables and the Tele 3 extend cables to
verify that the minimum torque value is achieved as
specified in Table 4-1.
b. If Tele 3 does not bottom out completely, loosen Tele
3 extend and retract cables. Extend the boom a few
feet. Tighten Tele 3 retract cables. Retract the boom
a few feet and tighten Tele 3 extend cables. Extend
and retract the boom a few times. Repeat until the
section bottoms out properly. Re-torque the Tele 3
retract cables and the Tele 3 extend cables to verify
that the minimum torque value is achieved as
specified in Table 4-1.
c. If Tele 4 is fully retracting early, loosen the Tele 4
extend and retract cables. Extend and retract the
boom a few feet. Tighten the Tele 4 extend cables,
Extend the boom a few feet and tighten Tele 4
retract cables. Retract the boom fully. Repeat until
the section bottoms out properly. Re-torque the Tele
4 retract cables and the Tele 4 extend cables to
verify that the minimum torque value is achieved as
specified in Table 4-1
.
d. If Tele 4 does not bottom out completely, loosen Tele
4 extend and retract cables. Extend the boom a few
feet. Tighten Tele 4 retract cables. Retract the boom
a few feet and tighten Tele 4 extend cables. Extend
and retract the boom a few times. Repeat until the
section bottoms out properly. Re-torque the Tele 4
retract cables and the Tele 4 extend cables to verify
that the minimum torque value is achieved as
specified in Table 4-1.
e. If Tele 2 extends (drifts) back out after the hydraulic
valve is in neutral, extend the boom a few feet.
Loosen Tele 3 retract cables slightly. Extend and
retract the boom a few times. If Tele 2 continues to
drift out, extend and then retract the boom. Tighten
Tele 3 extend cables slightly. Extend and retract the
boom fully. Repeat until Tele 2 does not drift back
out.
CAUTION
When tightening/loosening the cables, secure cable using
the flats at the front of the cable ends to prevent cable
twist. Do not use an impact wrench. Do not turn cable.
Turning the cable while adjusting will result in damage or
failure of the cable.