JLG E300 Service Manual - Manual (Page 90)

SECTION 4 - BOOM & PLATFORM
4-4 – JLG Lift – 3120772
6. Using a suitable lifting device, remove telescope cyl-
inder from boom sections.
7. Using a piece of tape, mark the length of hoses and
wires from front of fly boom and bottom of base
boom for reassembly.
8. Remove hardware securing the front wear pads on
base boom section, remove wear pads.
9. Remove hardware securing the power track to the
aft end of the fly boom section.
10. Using a suitable lifting device, remove fly boom from
boom section.
11. Remove hydraulic lines and electrical cables from
power track.
12. Remove hardware securing power track to the base
boom section. Remove power track.
Inspection
1. Inspect all boom pivot pins for wear, scoring or other
damage, and for tapering or ovality. Replace pins as
necessary.
2. Inspect lift cylinder pins for wear, scoring or other
damage, and for tapering or ovality. Ensure pin sur-
faces are protected prior to installation. Replace pins
as necessary.
3. Inspect telescope cylinder rod attach pin for wear,
scoring or other damage. Replace pin as necessary.
4. Inspect inner diameter of boom pivot bushings for
scoring, distortion, wear or other damage. Replace
bushings as necessary.
5. Inspect wear pads for wear.
6. Inspect all threaded components for damage such
as stretching, thread deformation, or twisting.
Replace as necessary.
7. Inspect structural units of boom assembly for bend-
ing, cracking, separation of welds, or other damage.
Replace boom sections as necessary.
Assembly of the Main Boom
1. Install power track to the attach point on the base
boom section. Secure power track with the attaching
hardware.
2. Install hydraulic lines and electrical cables into the
power track.
3. Install wear pads to the aft end of the fly section.
4. Using suitable lifting equipment, slide fly section into
the base section until power track attach point aligns
with holes in side of base section.
5. Attach the power track to the aft end of fly boom
section. Secure power track with the attaching hard-
ware.
6. Using suitable lifting equipment, slide fly boom sec-
tion out to gain access to telescope cylinder attach
pin hole.
7. Measure the distance between the telescope cylin-
der port block attach point on base boom section
and the attach point on fly boom section.
8. Connect a suitable auxiliary hydraulic power source
to the telescope cylinder port block.
9. Extend the telescope cylinder the distance of the
two attach points.
10. Secure the sling and lifting device at the telescope
cylinder’s approximate center of gravity, and lift the
cylinder to the aft end of the boom assembly.
WHEN INSERTING THE TELESCOPE CYLINDER INTO THE BOOM,
CARE MUST BE TAKEN NOT TO DAMAGE THE POWER TRACK
ASSEMBLY.
11. Slowly slide the telescope cylinder into boom
assembly, align rod end with attach point in fly sec-
tion. Insert pin and secure with retaining ring.
12. Align bolt holes at aft end of base boom section with
telescope cylinder port block. Secure telescope cyl-
inder with hardware.
13. Install wear pads at end of base boom section.
Using shims, adjust the adjustable wear pads to
zero clearance. Adjust pads alternately side to side,
so that fly boom section is centered in base boom
section.
14. Retract boom section fully. Using shims, adjust wear
pads at aft end of boom section to zero clearance.
Adjust pads alternately side to side, so that fly boom
section is centered in base boom section.
15. Disconnect auxiliary power source from telescope
cylinder.