
SECTION 3 - CHASSIS & TURNTABLE
3121619
3-3
3.4
STEERING CONTROL SYSTEM
There are three different modes of steering selectable by the
position of the steer select switch on the platform control
panel: crab, coordinated, and conventional two wheel steer-
ing. These are shown below.
Each wheel has its own steer cylinder, wheel angle sensor, axle
extend linear sensor, and proportional valve, allowing the con-
trol system to position each wheel to the ideal angle for all
steering modes and all steering commands. This is done
whether the axle is retracted, extended, or somewhere in
between. Changes in steering modes while drive is engaged
causes the wheels to automatically adjust to the appropriate
angle for the selected steering mode based on the position of
the inside front wheel. If the steer select switch is changed
without the footswitch depressed or the EMS is off, the wheels
will not move until the footswitch is depressed and a steering
or drive command has been initiated. The steering angles are
limited to +/- 20 degrees anytime the axles are not fully
extended. See the Axle Extension System for interaction with
the axle extension system. If a wheel cannot achieve its com-
manded angle within a specified time, it is considered
jammed. When a wheel is considered jammed during steering,
a fault is reported and the remaining wheels will continue to
their commanded position. The fault is cleared when the foot-
switch is cycled. If a wheel is jammed making it significantly
out of position, with regard to the other wheels, the drive
motors are restricted to their maximum displacement (slow
speed). Wheel angle sensor failures will result in an approxi-
mated steering control logic that will allow the operator to
move the machine until it can be repaired. The wheel at the
failed sensor will be driven based on the information available
from the other sensors. This wheel will not track perfectly and
will become farther out of position over time. When the wheel
becomes prohibitively out of position, the wheels can be
resynchronized by fully steering against the mechanical stops.
Axle extend sensor failures will result in an approximated
steering control logic that will allow the operator to move the
machine until it can be repaired. The axle at the failed sensor
Figure 3-1. Crab Steer
Figure 3-2. Coordinated Steer
Figure 3-3. 2 Wheel Steer
Summary of Contents for 1850SJ
Page 1: ...Service and Maintenance Manual Model 1850SJ 3121619 June 29 2018 Rev J AS NZS...
Page 2: ......
Page 21: ...3121619 xvii LIST OF FIGURES FIGURE NO TITLE PAGE NO Thispageleftblankintentionally...
Page 24: ...xx 3121619 LIST OF TABLES TABLE NO TITLE PAGE NO Thispageleftblankintentionally...
Page 50: ...SECTION 2 GENERAL 2 12 3121619 NOTES...
Page 55: ...SECTION 3 CHASSIS TURNTABLE 3121619 3 5 This page left blank intentionally...
Page 56: ...SECTION 3 CHASSIS TURNTABLE 3 6 3121619 Figure 3 4 Axle Hose Routing Sheet 1 of 2...
Page 57: ...SECTION 3 CHASSIS TURNTABLE 3121619 3 7 Figure 3 5 Axle Hose Routing Sheet 2 of 2...
Page 58: ...SECTION 3 CHASSIS TURNTABLE 3 8 3121619 Figure 3 6 Steering Axle Hydraulic Circuit...
Page 61: ...SECTION 3 CHASSIS TURNTABLE 3121619 3 11 Figure 3 9 Turntable Hydraulic System...
Page 92: ...SECTION 3 CHASSIS TURNTABLE 3 42 3121619 Figure 3 39 Swing Bearing Wear Tolerance...
Page 94: ...SECTION 3 CHASSIS TURNTABLE 3 44 3121619 Figure 3 41 Swing Bearing Removal Sheet 2 of 4...
Page 110: ...SECTION 3 CHASSIS TURNTABLE 3 60 3121619 Figure 3 54 Engine Electrical Circuit...
Page 169: ...SECTION 4 BOOM PLATFORM 3121619 4 7 Figure 4 1 Boom Hydraulic System...
Page 173: ...SECTION 4 BOOM PLATFORM 3121619 4 11 Figure 4 2 Boom Assembly Sheet 1 of 9...
Page 174: ...SECTION 4 BOOM PLATFORM 4 12 3121619 Figure 4 3 Boom Assembly Sheet 2 of 9...
Page 175: ...SECTION 4 BOOM PLATFORM 3121619 4 13 Figure 4 4 Boom Assembly Sheet 3 of 9...
Page 176: ...SECTION 4 BOOM PLATFORM 4 14 3121619 Figure 4 5 Boom Assembly Sheet 4 of 9...
Page 177: ...SECTION 4 BOOM PLATFORM 3121619 4 15 Figure 4 6 Boom Assembly Sheet 5 of 9...
Page 178: ...SECTION 4 BOOM PLATFORM 4 16 3121619 Figure 4 7 Boom Assembly Sheet 6 of 9...
Page 179: ...SECTION 4 BOOM PLATFORM 3121619 4 17 Figure 4 8 Boom Assembly Sheet 7 of 9...
Page 180: ...SECTION 4 BOOM PLATFORM 4 18 3121619 Figure 4 9 Boom Assembly Sheet 8 of 9...
Page 181: ...SECTION 4 BOOM PLATFORM 3121619 4 19 Figure 4 10 Boom Assembly Sheet 9 of 9...
Page 187: ...SECTION 4 BOOM PLATFORM 3121619 4 25 Figure 4 16 Boom Assembly Torque Values Sheet 1 of 4...
Page 188: ...SECTION 4 BOOM PLATFORM 4 26 3121619 Figure 4 17 Boom Assembly Torque Values Sheet 2 of 4...
Page 189: ...SECTION 4 BOOM PLATFORM 3121619 4 27 Figure 4 18 Boom Assembly Torque Values Sheet 3 of 4...
Page 190: ...SECTION 4 BOOM PLATFORM 4 28 3121619 Figure 4 19 Boom Assembly Torque Values Sheet 4 of 4...
Page 201: ...SECTION 4 BOOM PLATFORM 3121619 4 39 Figure 4 20 Hose Adjustment...
Page 202: ...SECTION 4 BOOM PLATFORM 4 40 3121619 Figure 4 21 Section 3 Boom Cables...
Page 203: ...SECTION 4 BOOM PLATFORM 3121619 4 41 Figure 4 22 Section 4 Boom Cables...
Page 204: ...SECTION 4 BOOM PLATFORM 4 42 3121619 Figure 4 23 Section 5 Boom Cables...
Page 205: ...SECTION 4 BOOM PLATFORM 3121619 4 43 Figure 4 24 Jib Hydraulics Sheet 1 of 7...
Page 234: ...SECTION 4 BOOM PLATFORM 4 72 3121619 Figure 4 44 Powertrack Shimming Instructions...
Page 239: ...SECTION 4 BOOM PLATFORM 3121619 4 77 Figure 4 49 Powertrack Hose Installation Sheet 1 of 4...
Page 240: ...SECTION 4 BOOM PLATFORM 4 78 3121619 Figure 4 50 Powertrack Hose Installation Sheet 2 of 4...
Page 241: ...SECTION 4 BOOM PLATFORM 3121619 4 79 Figure 4 51 Powertrack Hose Installation Sheet 3 of 4...
Page 242: ...SECTION 4 BOOM PLATFORM 4 80 3121619 Figure 4 52 Powertrack Hose Installation Sheet 4 of 4...
Page 252: ...SECTION 4 BOOM PLATFORM 4 90 3121619 NOTES...
Page 432: ...SECTION 5 BASIC HYDRAULIC INFORMATION HYDRAULIC SCHEMATICS 5 180 3121619 NOTES...
Page 527: ...SECTION 6 JLG CONTROL SYSTEM 3121619 6 95 Figure 6 36 LSS Installation Sheet 1 of 4...
Page 528: ...SECTION 6 JLG CONTROL SYSTEM 6 96 3121619 Figure 6 37 LSS Installation Sheet 2 of 4...
Page 529: ...SECTION 6 JLG CONTROL SYSTEM 3121619 6 97 Figure 6 38 LSS Installation Sheet 3 of 4...
Page 530: ...SECTION 6 JLG CONTROL SYSTEM 6 98 3121619 Figure 6 39 LSS Installation Sheet 4 of 4...
Page 710: ...SECTION 7 BASIC ELECTRICAL INFORMATION ELECTRICAL SCHEMATICS 7 118 3121619 NOTES...
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