JLG 40H Service Manual - Manual (Page 36)

SECTION 2 - PROCEDURES
2-16
– JLG Lift – 3120240
boom mid section; use a suitable slide hammer to
remove the pins.
WHEN REM OVING THE TELESC OPE CYLIN DER FROM THE
BOOM, IT MAY BE NECESSARY AT SOME POINT TO TURN THE
CY LIN DE R SL IGHT LY IN O RD ER TO CL EA R A S SE M B LIE S
MOUNTED WITHIN THE BOOM CARE MUST BE TAKEN TO MOVE
THE CYLINDER SLOWLY FROM THE BOOM, DAMAGE TO COM-
PONENTS MAY RESULT FROM FORCIBLE IMPACT WITH THESE
ASSEMBLIES.
22. Pull the cylinder partially from the rear of the boom
mid section; secure the cylinder with a suitable sling
and lifting device at approximately the center of
gravity.
23. Carefully remove the telescope cylinder and sheave
assembly. Place the cylinder on a suitable trestle.
24. Remove bolts and washers from the sheave pin;
remove the pin and the sheave assembly.
NOTE: Note and record the number and thickness of any
wear pad shims during wear pad removal.
25. Remove the bolts which secure the wear pads to the
inner surfaces of the boom mid section; remove the
wear pads from the top, sides and bottom of the mid
section.
26. Remove bolts and lock washers which secure the
chain block weldment to the aft end of the fly sec-
tion. Remove the cotter pins from the clevis pins
which secure the extension chain and retraction
chains to the block; remove the clevis pin, washers
and chains from the block.
27. Using suitable lifting equipment, remove the fly sec-
tion from the mid section; place the fly section on a
suitable trestle.
28. Remove the bolts which secure the wear pads to the
aft ends of the fly and mid sections; remove the wear
pads from the boom sections.
Inspection.
NOTE: Steps 1, thru 4 apply to 3 Section Boom Only.
1. Inspect all sheaves (extend chains, retract chains
and telescope cylinder) for excessive groove wear,
burrs or other damage. Replace sheaves as neces-
sary.
2. Inspect extend chain and retract chain sheave bear-
ings for wear, scoring, or other damage, and for
ovality. Replace bearings as necessary, ensuring
they are installed flush with sheave surface.
3. Inspect extend chain and retract chain sheave pins
for scoring, tapering, ovality and evidence of correct
lubrication. Replace pins as necessary.
4. Inspect telescope cylinder sheave pin for tapering,
scoring, ovality and evidence of correct lubrication.
Replace pin as necessary.
5. Inspect boom pivot pin for wear, scoring or other
damage, and for tapering or ovality. Replace pin as
necessary.
6. Inspect upper lift cylinder attach pin for tapering,
ovality, scoring, wear, or other damage. Ensure pin
surfaces are protected prior to installation. Replace
pin as necessary.
NOTE: Steps 7 and 8 apply to 3 Section Boom Only.
7. Inspect telescope cylinder trunnion attach pin for
tapering, ovality, scoring, wear, or other damage.
Replace pin as necessary.
8. Inspect extend chain attach clevis pins for wear,
scoring, or other damage. Replace pins as neces-
sary.
9. Inspect telescope cylinder rod attach pin for scoring,
wear, or other damage. Replace pin as necessary.
10. Inspect inner diameter of boom pivot bushing for
scoring, distortion, wear, or other damage. Replace
bushing as necessary.
11. Inspect all wear pads for excessive wear or damage.
Replace pads when worn to within 1/8 inch (3.2 mm)
of insert.
NOTE: Step 12 applies to 3 Section Boom Only.
12. Inspect extend and retract chains and chain attach
components for cracks, stretching, distortion, or
other damage. Replace components as necessary.
13. Inspect all threaded components for damage such
as stretching, thread deformation, or twisting.
Replace as necessary.
14. 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 the inside dimensions of the base and mid
sections to determine the number of shims required
for proper lift.
NOTE: Step 2 applies to 2 Section Boom Only.