JLG 660SJ ANSI Service Manual - Manual (Page 155)

SECTION 4 - BOOM & PLATFORM
3120718 – JLG Lift – 4-19
Inspection
NOTE: Refer to Section 2 - General.
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.
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 upright attach point bear-
ings for scoring, distortion, wear, or other damage.
Replace bearing as necessary.
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
damage. Replace boom sections as necessary.
8. Inspect powertrack for damage such as cracking,
wear, or other damage. Replace as necessary.
Assembly
NOTE: When installing fly section wear pads, install same
number and thickness of shims as were removed
during disassembly.
1. Measure inside dimensions of the tower base sec-
tion to determine the number of shims required for
proper lift.
2. Install side, top and bottom wear pads to the aft end
of tower fly section; shim evenly to the measure-
ments of the inside of base boom section.
WHEN ASSEMBLING TOWER BOOM SECTIONS, ENSURE THAT
THE BOOM SLIDING TRAJECTORIES HAVE BEEN CLEARED OF
CHAINS, TOOLS, AND OTHER OBSTRUCTIONS.
3. Align upright leveling cylinder with attach holes in
tower fly boom. Using a soft head mallet, install the
cylinder pin into tower fly boom and secure with
mounting hardware.
4. Align tower telescope cylinder with attach holes in
tower fly boom. Using a soft head mallet, install the
cylinder pin into tower fly boom and secure with
mounting hardware.
5. Secure the sling and lifting device at the tower fly
boom assembly’s approximate 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 into the forward position of the
tower base boom section. Shim boom, if necessary,
for a total of 2/10 inch (0.20) clearance.
8. Align the cylinder with the slots at aft end of tower
base boom section, then 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
hardware.
11. Properly route the hoses and wiring harnesses
through bracket at aft end of tower base boom sec-
tion.
12. Pull hoses and wiring harnesses through hose
bracket to the mark on hoses and harnesses from
previous disassembly and clamp for proper length.
13. Route hoses and harnesses through powertrack,
push tubes, then through holes in side of tower fly
boom nose. Secure hoses and harnesses with
hoses brackets.