SECTION 2 - GENERAL
3121273
– JLG Lift –
2-7
Changing Hydraulic Oil
1. Use of any of the recommended crankcase or
hydraulic oils eliminates the need for changing the
oil on a regular basis. However, filter elements must
be changed annually unless operating in extreme
conditions. If it is necessary to change the oil, use
only those oils meeting or exceeding the specifica-
tions appearing in this manual. If unable to obtain
the same type of oil supplied with the machine, con-
sult local supplier for assistance in selecting the
proper equivalent. Avoid mixing petroleum and syn-
thetic base oils. JLG Industries recommends chang-
ing the hydraulic oil annually.
2. Use every precaution to keep the hydraulic oil clean.
If the oil must be poured from the original container
into another, be sure to clean all possible contami-
nants from the service container. Always replace the
filter and clean magnet any time the system oil is
changed.
3. While the unit is shut down, a good preventive main-
tenance measure is to make a thorough inspection
of all hydraulic components, lines, fittings, etc., as
well as a functional check of each system, before
placing the machine back in service.
NOTE:
Refer to section 4 for oil checking and oil changing
procedure.
Lubrication Specifications
Specified lubricants, as recommended by the component
manufacturers, are always the best choice, however,
multi-purpose greases usually have the qualities which
meet a variety of single purpose grease requirements.
Should any question arise, regarding the use of greases in
maintenance stock, consult your local supplier for evalua-
tion. Refer to Section 1, Table 1-11, Lubrication Specifica-
tions for an explanation of the lubricant key designations.
2.5 CYLINDER DRIFT TEST
Maximum acceptable cylinder drift is to be measured
using the following methods.
Platform Drift
Measure the drift of the platform to the ground. Fully ele-
vate the platform. Maximum allowable drift is 2 inches (5
cm) in 10 minutes. If the machine does not pass this test,
proceed with the following.
Cylinder Drift
Drift is to be measured at the cylinder rod with a calibrated
dial indicator. The cylinder oil must be at ambient temper-
ature and temperature stabilized.
The cylinder must have the normal load, which is the nor-
mal platform load applied.
If the cylinder passes this test, it is acceptable.
NOTE:
This information is based on 6 drops per minute cyl-
inder leakage.
Table 2-3. Cylinder Drift
Cylinder Bore Diameter
Max. Acceptable Drift
in 10 Minutes
inches
mm
inches
mm
3
76.2
0.026
0.66
3.5
89
0.019
0.48
4
101.6
0.015
0.38
5
127
0.009
0.22
6
152.4
0.006
0.15
7
177.8
0.005
0.13
