JLG 740A, Service And Maintenance Manual

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SECTION 4 - BOOM & PLATFORM
4-18 – JLG Lift – 3121160
4.8 ARTICULATING JIB BOOM
Removal
1. For platform/support removal see platform/support
removal diagram.
2. Position the articulating jib boom level with the
ground.
3. Remove mounting hardware from slave cylinder pin
#1. Using a suitable brass drift and hammer, remove
the cylinder pin from articulating jib boom.
4. Remove mounting hardware from articulating jib
boom pivot pin #2. Using a suitable brass drift and
hammer, remove the pivot pin from boom assembly.
Disassembly
1. Remove mounting hardware from articulating jib
boom pivot pins #3 and #4. Using a suitable brass
drift and hammer, remove the pins from articulating
jib boom pivot weldment.
2. Remove mounting hardware from rotator support
pins #5 and #6. Using a suitable brass drift and
hammer, remove the pins from rotator support.
3. Remove mounting hardware from lift cylinder pin
#7. Using a suitable brass drift and hammer, remove
the cylinder pin from articulating jib boom.
Inspection
NOTE: When inspecting pins and bearings Refer to Section
2 -
Pins and Composite Bearing Repair Guidelines.
1. Inspect articulating fly boom pivot pin for wear, scor-
ing, tapering and ovality, or other damage. Replace
pins as necessary.
2. Inspect articulating fly boom pivot attach points for
scoring, tapering and ovality, or other damage.
Replace pins as necessary.
3. Inspect inner diameter of articulating fly boom pivot
bearings for scoring, distortion, wear, or other dam-
age. Replace bearings as necessary.
4. Inspect lift cylinder attach pin for wear, scoring,
tapering and ovality, or other damage. Ensure pin
surfaces are protected prior to installation. Replace
pins as necessary.
5. Inspect inner diameter of rotator attach point bear-
ings for scoring, distortion, wear, or other damage.
6. Inspect all threaded components for damage such
as stretching, thread deformation, or twisting.
Replace as necessary.
7. Inspect structural units of articulating jib boom
assembly for bending, cracking, separation of
welds, or other damage. Replace boom sections as
necessary.
Figure 4-6. Location of Components-Articulating Jib