JLG 4017RS Service Manual - Manual (Page 74)

Boom
3-34 3614RS, 4017RS
Edge Wear
Check the chain for wear on the link plate edges caused
by running back and forth over the sheave. The
maximum reduction of material should not exceed 5%.
Measure and compare to a normal link plate height by
measuring a portion of chain that does not run over the
sheave. If the measured plate height (1) is 5% less than
the normal plate height (2), discard and replace the
chain.
Elongation
It is important to measure the chain in the section that
moves over the sheaves because it receives the most
frequent articulation. Measuring the chain near its clevis
terminals could give an inaccurate reading. The ends of
the chains, near the clevis terminal, will not have flexed
as frequently, if at all, as the middle of the chains.
It is best to measure in 12 pin increments from pin
center to pin center. For example, if the links are
25 mm (1 in) from pin center to pin center, the distance
should be 305 mm (12 in). If the links are 19 mm (.75 in)
apart, the distance after 12 pins should be 229 mm (9
in).
If the distance measured (3) is 3% greater than the
normal length (4), discard and replace the chain.
3.15.3 Inspection Guidelines - 4017RS
1. Park the machine on a firm, level surface, raise the boom
to a horizontal (level) position, place the transmission in
(N) NEUTRAL, engage the park brake switch.
2. Fully extend the boom until the extend chain is taut.
Shut the engine off.
3. The extend chains will be visible for inspection with the
vehicle in this state.
4. While doing the chain inspection, check all chain clevis
ends for distortion or cracking and sheaves for bearing
wear or grooving from the chain.
5. Inspect the retract chains every 1000 hours of
operation. Refer to the Service Manual for proper
procedure.
6. Inspect the chains for the following conditions:
Edge Wear
Check the chain for wear on the link plate edges caused
by running back and forth over the sheave. The
maximum reduction of material should not exceed 5%.
This can be compared to a normal link plate height by
measuring a portion of chain that does not run over the
sheave.
a. Extend Chains (fourth to third section)
The extend chains between the fourth and third boom
sections measures 18 mm (.713 in) (1). If the
measurement of the worn chain is less than 17 mm
(.677 in) (2), the chain should be replaced.
b. Extend Chains (third to second section)
The extend chains between the third and second boom
sections measures 29,6 mm (1.2 in) (1). If the
measurement of the worn chain is less than 28,6 mm
(1.1 in) (2), the chain should be replaced.
MZ1463
2 1
MY1360
3
4
MZ1463
1 2