Service Manual Instruction Manual

SECTION 4 - BOOM & PLATFORM
4-6 – JLG Lift – 3121616
INSPECTION
NOTE: Replace worn or damage components as needed.
1. Inspect tower boom pivot pin for wear, scoring, tapering
and ovality, or other damage.
2. Inspect tower boom pivot attach points for scoring,
tapering and ovality, or other damage.
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, tapering
and ovality, or other damage. Ensure pin surfaces are
protected prior to installation.
5. Inspect inner diameter of upright attach point bearings
for scoring, distortion, wear, or other damage.
6. Inspect all threaded components for stretching, thread
deformation, twisting, or other damage.
7. Inspect structural units of tower boom assembly for
bending, cracking, separation of welds, or other dam-
age.
8. Inspect powertrack for cracking, wear, or other damage.
ASSEMBLY
NOTE: Install same number and thickness of shims as removed.
1. Measure inside dimensions of tower base section to
determine number of shims required for proper lift.
2. Install side, top and bottom wear pads to aft end of
tower fly section. Shim evenly to measurements of the
inside of base boom section.
ENSURE BOOM SLIDING AREAS ARE CLEAR OF CHAINS, TOOLS, AND OTHER
OBJECTS WHEN ASSEMBLING BOOM SECTIONS.
3. Align upright leveling cylinder with attach holes in
tower fly boom. Using a soft head mallet, install the cyl-
inder pin into tower fly boom and secure with mounting
hardware.
4. Align tower telescope cylinder with attach holes in
tower fly boom. Install cylinder pin in tower fly boom
using a soft head mallet. Secure with mounting hard-
ware.
5. Secure sling and lifting device at tower fly boom center
of gravity.
6. Slide tower fly boom assembly into the tower base
boom section. Shim boom, if necessary, for a total of 1/
16 inch (0.062) clearance.
7. Install wear pads in forward position of tower base
boom section. Shim boom, if necessary, for a total of 2/
10 inch (0.20) clearance.
8. Align cylinder with slots at aft end of tower base boom
section. Secure cylinder with mounting hardware.
9. Install powertrack to attach point on the tower base
boom section, then secure with mounting hardware.
10. Attach push tubes to the powertrack and attach point
on the tower fly boom section; with mounting hard-
ware.
11. Properly route hoses and wiring harnesses through
bracket at aft end of tower base boom section.
12. Pull hoses and wiring harnesses through hose bracket to
mark on hoses and harnesses from disassembly. Clamp
for proper length.
13. Route hoses and harnesses through powertrack. Push
tubes through holes in side of tower fly boom nose.
Secure hoses and harnesses with hoses brackets.
INSTALLATION
1. Position tower boom assembly on turntable using a suit-
able lifting device. Align pivot holes in boom and turnta-
ble.
2. Install tower boom pivot pin. Ensure location of hole in
pin is aligned with attach point on turntable.
3. If necessary, gently tap pin into position with soft
headed mallet. Secure pin mounting hardware.
4. Using all applicable safety precautions, operate lifting
device and position lower boom lift cylinder so holes in
cylinder rod end and tower boom structure are aligned.
Insert lift cylinder pin, ensuring that location of hole in
pin is aligned with attach point on tower boom.
5. Connect all wiring connections at ground controls.
6. Connect all hydraulic lines running from aft end of tower
boom assembly to ground controls.
7. Using suitable lifting device, position upright on tower
boom assembly so pivot holes in upright and tower
boom are aligned.
8. Using all applicable safety precautions, operate lifting
device and position upright leveling cylinder so holes in
cylinder barrel end and upright structure are aligned.
Insert level cylinder pin, ensuring that location of hole in
pin is aligned with attach point on upright.
9. Align upper lift cylinder with attach holes in upright.
Using a soft head mallet, install cylinder pin upright and
secure with mounting hardware.
10. Align master cylinder with attach holes in upright. Using
Install cylinder pin with soft head mallet. Secure with
mounting hardware.