JLG 110HX Service Manual - Manual (Page 34)

SECTION 2 - PROCEDURES
2-10 – JLG Lift – 3120864

Also, more than one crack can often appear on a
link plate. In addition to rusting, this condition can
be caused by exposure to an acidic or caustic
medium or atmosphere. Stress corrosion is an envi-
ronmentally assisted failure. Two conditions must be
present - corrosive agent and static stress.

In the chain, static stress is present at the aperture
due to the press fit pin. No cycle motion is required
and the plates can crack during idle periods. The
reactions of many chemical agents (such as battery
acid fumes) with hardened metals liberate hydrogen
which attacks and weakens the metal grain struc-
ture.
8. Chain Anchors and Sheaves: An inspection of the
chain must include a close examination of chain
anchors and sheaves. Check chain anchors for wear
breakage and misalignment. Anchors with worn or
broken fingers should be replaced. They should
also be adjusted to eliminate twisting the chain for
an even load distribution.

Sheaves should be inspected for worn flanges,
which would indicate misalignment, and wear on the
outside diameter of the sheave. A worn sheave can
mean several problems, as follows:

1. Chains too tight.
2. Sheave bearings/pin bad.
3. Bent/misaligned chains.
Auxiliary Boom Chains
The auxiliary boom chains are located on the top and bot-
tom of the boom. One end of the top chain is attached to
an adjustable clevis on top of the front end of the base
section, and uses belleville washers and adjusting nuts to
adjust chain tension. The other end of the top chain is
attached to a fixed clevis on top of the outer mid section.
One end of the bottom chain is attached to an adjustable
clevis attached to the bottom front of the inner mid sec-
tion. The other end of the bottom chain is attached to a
fixed clevis on the bottom of the fly section. A limit switch
is installed adjacent to the adjustable clevis on the top of
the base section and, when tripped, shuts down the
machine. Adjust chain tension for the top chain so there is
no slack in the chain and torque the adjusting nut to 18
Nm. Set the switch cam so the switch trips when the
belleville washers compress 1 to 1.3 cm. Adjust chain ten-
sion for the bottom chain so there is no slack in the chain
and torque the adjusting nut to 18 Nm. Triple stack all
belleville washers as shown.
REPLACE THE BELLEVILLE WASHERS ONCE THEY HAVE BEEN
COMPRESSED.
2.7 WEAR PADS
1. Shim up wear pads to within 0.8 mm tolerance
between wear pad and adjacent surface.
2. Replace wear pads when worn within 3.2 mm of
threaded insert.
2.8 DRIFT TEST
NOTE: It is recommended that the machine be shut down in
the test mode for at least one hour prior to beginning
the drift test. This will allow the oil temperature in the
cylinder to stabilize with the ambient temperature.
Thermal expansion or retraction of the hydraulic oil
can greatly affect cylinder movement.
Telescope Cylinder
NOTE: Switches referenced in this procedure are located on
the Ground Control Panel.
1. Activate hydraulic system, properly set extendable
axles and position boom in stowed position; adhere
to all safety precautions.
ABNORMAL PROTRUSION OR
TURNED PINS
ARC-LIKE CRACKED PLATES
(STRESS CORROSION)
TRIPLE STACK
WASHERS