JLG 740AJ, Руководство по обслуживанию и ремонту

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SECTION 4 - BOO M & PLATFOR M
3121160 4-19
4.8 TOWER BOOM ASSEMBLY
Removal
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDIATELY AFTER DIS-
CONNECTING LINES TO AVOID ENTRY OF CONTAMINANTS INTO SYSTEM.
1. Remove the main boom assembly. Refer to Section 4.6,
Main Boom Assembly.
2. Remove the upright. Refer to Section 4.7, Upright.
3. Using an overhead crane or suitable lifting device, sup-
port the entire Tower Boom Assembly and separately
support the tower lift cylinder.
4. Remove mounting hardware from tower lift cylinder rod
end. With a brass drift and hammer, remove the tower
lift cylinder pin #1 disconnecting the tower lift cylinder.
5. Remove mounting hardware from the tower boom pivot
pin. Using a suitable brass drift and hammer, remove pin
#2 from turntable assembly.
6. Using all applicable safety precautions, carefully lift the
Tower Boom Assembly clear of turntable and lower to
ground or a suitable supported work surface.
7. Remove mounting hardware from upright leveling cyl-
inder rod end. Using a suitable brass drift and hammer,
remove the upright cylinder pin #3, disconnecting the
upright cylinder from tower boom. Remove with suit-
able lifting device.
Inspection
NOTE: Refer to Section 2, Pins and Composite Bearing Repair
Guidelines.
1. Inspect tower boom pivot pin for wear scoring, tapering,
and ovality, or other damage. Replace pins as necessary.
2. Inspect tower boom pivot attach points for scoring,
tapering, and ovality, or other damage. Replace pins as
necessary.
3. Inspect inner diameter of tower boom pivot bearings for
scoring, distortion, wear, or other damage.
4. Inspect lift cylinder attach pin for wear, scoring, taper-
ing, and ovality, or other damage. Ensure pin surfaces
are protected prior to installation. Replace pins as neces-
sary.
5. Inspect inner diameter of upright attach point bearings
for scoring, distortion, wear, or other damage. Replace
bearing as necessary. (See Section 5 Cylinder Repair for
Bearing Replacement).
6. Inspect all threaded components for damage such as
stretching, thread deformation, or twisting. Replace as
necessary.
7. Inspect structural units of tower boom assembly for
bending, cracking, separation of welds, or other dam-
age. Replace boom sections as necessary.
Figure 4-7. Tower Boom Removal
UPRIGHT
TOWER BOOM
TURNTABLE
1
2
3
UPRIGHT LEVEL
CYLINDER
TOWER BOOM
LIFT CYLINDER