JLG 4017 Service Manual - Manual (Page 29)

3.5 4017
Boom
3. Use a suitable sling around the third section boom to
take any pressure off of wear pads to make pad
removal easier.
Note: Before removing the extend chains, measure the
distance (1) between the face of the jam nut to the end of
the chain clevis on all four extend chains. This
measurement will be used when reassembling the
boom.
4. At the bottom front of the first section boom remove
the jam nuts and nuts and washers from the two
extend chain clevises. Remove clips and pins from
the two clevises and remove clevis from each chain.
5. At the bottom front of the second section boom
remove the jam nuts and nuts and washers from the
two extend chain clevises. Remove clips and pins
from the two clevises and remove clevis from each
chain.
6. At the rear of boom, loosen and unscrew both tilt
hoses and both auxiliary hoses from bulkhead on
hose carrier. Plug the hose ends and cap the
bulkhead fittings to prevent dirt and debris from
entering the hydraulic system.
7. Remove the clip and pin from both retract chain
clevises that are attached to the rear of the third
section boom. The pins can be removed through the
access holes at the bottom left and right sides of the
first section boom. Do not remove the clevises
8. Remove the clip and pin from the retract chain clevis
that is attached to the rear of the fourth boom
section. Do not remove the clevis.
9. Pull the second section boom out
152 mm to 203 mm (6 in to 8 in) to be able to loosen
and remove all the bolts and remove all the wear
pads, backing plates and shims from the front inside
of the first section boom. Tag each pad, backing
plate, shim and bolts from each location.
10. Pull the third boom section out 152 mm to 203 mm
(6 in to 8 in) to be able to access the wear pad bolts
on the rear of the second section boom. Remove the
top left and right side wear pads, backing plates and
shims (one on each side) from the second boom
section. Loosen the bottom rear wear pad bolts and
remove the shims from the second boom section to
gain the necessary clearance to be able to remove
the second boom section from the first boom
section. Tag each pad, backing plate, shim and bolts
from each location.
11. Using a sling around the front of the second boom
section, lift and slide the three boom sections 3/4 of
the way out of the first boom section. Set the boom
head down on a suitable support, then center the
sling to be able to balance the three boom sections
being removed. Carefully pull the three boom
sections (3) the remainder of the way out of the first
boom section and set the three boom sections down
on suitable supports.
12. Remove the clip and pin holding each retract chain
from the inside of the first boom section. Clean and
inspect chains. Replace if damaged.
13. Unscrew the tilt and auxiliary hoses from tubes at
bottom front of first boom section. Plug the tilt and
auxiliary hoses and cap the tubes to prevent dirt and
debris from entering hydraulic system. Clean and
inspect the hoses. Replace if damaged.
14. Inspect the boom and welds. Consult the local JLG
distributor or the JLG Service Department if structural
damage is detected.
15. Inspect hoses, hardware, wear pads, mounting
points, chains and other components visible with the
first boom section. Replace any item if damaged.
(Refer to Section 3.4.1, 3.4.1. “Boom Chain
Inspection,” and Section 3.7.1, 3.7.1. “Wear Pad
Inspection.”)
Note: It is recommended that if any chain or hose is
damaged that ALL chains or hoses are replaced.
MZ0790
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