JLG 340AJ Service Manual - Manual (Page 72)

SECTION 3 - CHASSIS & TURNTABLE
3-32 – JLG Lift – 3121259
3.9 CHASSIS TILT INDICATOR SYSTEM
The Chassis Tilt Indicator System measures the turntable angle
with regard to level ground. The tilt sensor has two settings;
5.0°/3.0° (depending on market) and 6.0° degrees. The 5.0°/
3.0° angle is set by choosing the desired market selection for
the machine based on machine setup using the JLG Analyzer.
The 5.0°/3.0° angle is used to warn the operator of an excessive
slope by means of the chassis tilt light on the platform display
panel. The tilted condition exists when the chassis tilt reading
is greater than or equal to the setting selected in the analyzer
for a period of 4 seconds or longer. The tilted condition will be
cleared if the tilt reading is less than the selected setting for a
period of 1 second. When used in conjunction with the
Beyond Transport - Drive Speed Cutback System, the tilt sen-
sor will cause an alarm to sound and automatically put all
functions in the creep speed mode. The operator is responsi-
ble for preventing the machine from reaching an unstable
position.
The 6° angle is used only for the purpose of automatically
slowing drive speed when this angle is reached and the boom
is in Transport position. When the boom is in Transport Posi-
tion and the chassis is at or above 6° for a period of 1 second or
longer, the drive system will automatically switch into Max
Torque mode. This condition will be cleared if the chassis tilt
reading is less than 5 degrees for a period of 1 second or lon-
ger.
The JLG Control System responds to indicated angle readings
0.5 degree smaller than the required angles to account for cal-
ibration and sensor variation.
The machine’s chassis tilt is measured by a pair of fluid-based
sensors imbedded within the Ground Module. These sensors
measure chassis tilt from side-to-side and from front-to-back.
The ground module uses one tilt sensor to measure machine
angle and uses the second sensor to compare against the first
one to ensure the angle reading is reliable.
3.10 SWING MOTOR
IF THE HYDRAULIC SYSTEM FLUID BECOMES OVERHEATED [IN EXCESS OF
200°F (93.3°C)], SEALS IN THE SYSTEM CAN SHRINK, HARDEN OR CRACK,
THUS LOSING THEIR SEALING ABILITY.
Figure 3-30. Swing Motor - Cutaway