JLG 660SJ Service Manual - Manual (Page 112)

SECTION 4 - BOOM & PLATFORM
4-10 – JLG Lift – 3120840
8. Inspect inner diameter of boom pivot bushing for
scoring, distortion, wear, or other damage. Replace
bearing as necessary. (See section 2 General).
9. Inspect all wear pads for excessive wear or other
damage. Replace pads when worn to within 3.2 mm
of threaded insert.
10. Inspect extend and retract wire rope attach point
components for cracks, stretching, distortion, or
other damage. Replace components as necessary.
11. Inspect all threaded components for damage such
as stretching, thread deformation, or twisting.
Replace as necessary.
12. Inspect structural units of boom assembly for bend-
ing, cracking, separation of welds, or other damage.
Replace boom sections 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 base and mid
sections to determine the number of shims required
for proper lift.
2. Measure inside dimensions of the mid section to
determine the number of shims required for proper
lift.
3. Install side, top and bottom wear pads to the aft end
of fly section; shim evenly to the measurements of
the inside of mid section.
4. Install retract wire ropes into aft end of fly section,
route wire ropes thru holes in side of fly boom sec-
tion and pull into slot.
5. Install side, top and bottom wear pads to the aft end
of mid section; shim evenly to the measurements of
the inside of mid section.
WHEN ASSEMBLING BOOM SECTIONS, ENSURE THAT THE
BOOM SLIDING TRAJECTORIES HAVE BEEN CLEARED OF
CHAINS, TOOLS, AND OTHER OBSTRUCTIONS.
6. Shim the insides of the boom sections for a total of
1.6 mm clearance (if the action is centered, there will
be 0.8 mm clearance on each side).
7. Slide fly boom section into the mid boom section.
Shim boom, if necessary, for a total of 1.6 mm clear-
ance.
8. Install wear pads into the forward position of the mid
boom section. Shim boom, if necessary, for a total of
5 mm clearance.
9. Properly position the retraction wire rope sheaves
assemblies at the aft end of the mid boom section;
ensure all sheave-to-mounting block attachment
holes align. Install the sheave pins and secure them
Figure 4-14. Routing Installation of Retract Wire Ropes