JLG 4017 Service Manual - Manual (Page 41)

3.17 4017
Boom
e. Removing Extend and Retract Chains
The four extend chains and the three retract chains can
only be removed during a complete boom teardown.
While doing the chain inspection, check all chain clevis
ends for distortion or cracking and sheaves for bearing
wear or grooving from the chain.
If during the inspection, any chain is found to be damaged
or stretched, the chain must be replaced. It is
recommended that when any chain is replaced, that all
the chains and clevis’ be replaced at the same time.
3.4.4 Chain Lubrication
After inspection and before being returned to service,
chains must be lubricated with a quality chain lubricant
(“LUBRIPLATE” Chain & Cable Fluid, “LPS3” or
equivalent).
The lubricant must penetrate the chain joint to prevent
wear. Applying lubricant to the external surfaces will
prevent rust, but the chains should be articulated to
make sure the lubricant penetrates to the working
surfaces between the pins and links.
To prepare the chain for lubrication, the chain plates
should be brushed with a stiff brush or wire brush to
clear the space between the plates so that lubricant can
penetrate to the working surfaces.
Lubricant may be applied with a narrow paint brush or
directly poured on, but the chain should be well flooded
with lubricant and the boom should be extended and
retracted to be sure that the lubricant penetrates to the
working surfaces. All surplus lubricant should be wiped
away from the external surfaces. DO NOT use a solvent
for this wiping operation.
Regular application of lubricant is necessary to make
sure that all working surfaces are adequately lubricated.
In extremely dusty conditions, it may be necessary to
lubricate the chains more often.
Lubrication of chains on vehicles working consistently in
extreme hot or cold conditions requires special
consideration. It is important that a reputable lubrication
specialist, a JLG Distributor or the vehicle distributor be
consulted for guidance.
3.5 BOOM SECTION SEPARATION
ADJUSTMENT
The second, third and fourth boom sections are set to
dimensions between each section. The first and second
boom sections are connected by the extend/retract
cylinder which has no adjustment.
The third and fourth boom sections can be adjusted by
loosening or tightening the extend chains and the retract
chains.
1. Fully retract the boom and raise the boom to a
horizontal position. Place the transmission control
lever in (N) NEUTRAL, engage the park brake
switch.
2. Measure the distance between the boom sections
(1). If adjustments are needed, extend the boom out
0,91 m to 1,2 m (3 ft to 4 ft). Shut off machine.
3. Loosen the locknuts on the extend chains and the
retract chains and adjust as needed.
a. To increase the separation distance: Loosen the
retract chains locknut on the rear of the third or
fourth boom sections one or two turns and
tighten the extend chain locknuts on the first and
second boom sections equally the same number
of turns. A minimum of one full thread on the
clevis must protrude beyond the locknut.
b. To decrease the separation distance: Loosen the
extend chain locknuts at the front of the first or
second boom sections equally one or two turns
and tighten the retract chains locknut the same
number of turns. A minimum of one full thread
on the clevis must protrude beyond the locknut.
797mm
31.378”
499mm
19.645”
229mm
9.016”
37mm
1.45”
20mm
.787”
1