Manitowoc Grove RT770E - Rt770 E Service Manual Boom Section 4 Boom

4-1
Published 11/26/2014, Control # 447-05
RT770E SERVICE MANUAL BOOM
4
GROVE
SECTION 4
BOOM
SECTION CONTENTS
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Boom Nose Sheaves . . . . . . . . . . . . . . . . . . . . . 4-21
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-32
Functional Check . . . . . . . . . . . . . . . . . . . . . . . . 4-33
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33
Boom Alignment and Servicing. . . . . . . . . . . . . . 4-33
Boom Extension and Retraction Cables . . . . . . 4-33
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34
Telescope Circuit . . . . . . . . . . . . . . . . . . . . . . . . . 4-37
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . 4-37
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39
Removal And Installation . . . . . . . . . . . . . . . . . . . 4-40
Disassembly And Assembly . . . . . . . . . . . . . . . . 4-40
Lift Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41
Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . 4-41
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41
Lift Cylinder Removal. . . . . . . . . . . . . . . . . . . . . . 4-43
Disassembly and Assembly. . . . . . . . . . . . . . . . . 4-43
Lift Cylinder Installation . . . . . . . . . . . . . . . . . . . . 4-43
Bi-Fold Boom Extension. . . . . . . . . . . . . . . . . . . . 4-45
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45
Boom Extension Rigging Mode . . . . . . . . . . . . . . 4-45
Erecting the Boom Extension . . . . . . . . . . . . . . . 4-45
Stowing the Boom Extension. . . . . . . . . . . . . . . . 4-52
Setting the Folding Swingaway Offset . . . . . . . . . 4-54
Boom Extension Alignment Device Adjustment. . 4-55
Swingaway Mounting Adjustment . . . . . . . . . . . . 4-55
Hook Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-56
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-56
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-56
DESCRIPTION
A five section 11 m to 42 m (35.9 ft to 138 ft), full power,
sequenced, and synchronized boom (Figure 4-1) is installed
on this crane.
The boom utilizes one telescope cylinder to extend and
retract Tele 1 and Tele 2, and a synchronized cable system to
extend and retract Tele and 4. The telescoping boom
sections are supported on graphite impregnated nylatron
wear pads. Side wear pads prevent metal to metal contact
between the tele sections.
Boom assembly lift is provided by one lift cylinder. Boom
elevation is from -3° to 78°.
An optional auxiliary boom nose (rooster sheave) is available
for the boom to simplify single part cable usage. The rooster
sheave is installed on the main boom nose and is secured by
pins that pass through the rooster sheave and main boom
nose.
A 10.1 m (33 ft) fixed offsetable or a 10.1 m to 17.07 m (33 ft
to 56 ft) folding offsetable swingaway boom extension is
provided to obtain additional boom reach. Optional inserts
are available for additional reach.
The bi-fold boom extension mounts directly to the boom
nose utilizing a four point attachment. In addition, the bi-fold
extension base section and/or fly section can be stowed on
the right side of the boom base section.