JLG 1100S Service Manual - Manual (Page 44)

SECTION 3 - CHASSIS & TURNTABLE
3-2 – JLG Lift – 3121256
3.2 EXTENDING AXLES
The Axle Extension System allows each of the four axles
to be extended and retracted together while maintaining
full steering control as the machine is driven. The system
allows the axles to extend or retract only while the boom is
in the transport position and in order to minimize wheel
scrubbing during axle movement, a minimum drive speed
must be attained before axle extension/retraction will be
permitted. The system uses four limit switches (one at
each axle) to sense when the axles are fully extended. If
any of the switches are not made, the control system con-
siders the axles retracted. To extend/retract the axles, the
user engages the axle extend/retract switch on the plat-
form console and the drive control at the same time. The
axle set indicator will be off when the axles are not fully
extended and the axle extend/retract switch is not
engaged. It will flash while the axles are extending or
retracting and will be on constantly when the axles are
fully extended. With the axles not fully extended, the boom
is restricted to operation within the transport position. If a
signal from any axle extend sensing switch is lost when
the boom beyond the transport position, the axle set indi-
cator will flash and drive/steer functions will be disabled
until the boom is brought back into the transport position.
The steering angle will be automatically limited to +/- 25
degrees anytime the axles are not fully extended. If the
wheel angle is more than +/- 25 degrees when the axle
retract command is engaged, the control system will auto-
matically reduce the wheel angle to 25 degrees during
axle retraction.
NOTE: For more detailed information concerning system
adjustment and operation, refer to Section 6 - JLG
Control System.
3.3 AXLE LIMIT SWITCH ADJUSTMENT
PROCEDURE
1. Fully extend the axles.
2. Initially position the limit switch arm straight.
3. Select the mounting plate bolt pattern to position the
switch roller within 0.125 inches (3.1 mm) from the
edge of the axle cutout. It may be necessary to repo-
sition the switch arm ±10° to accomplish this.
4. Ensure the arm will clear the axle (without bottoming
out to 70° stroke of the switch) in the retracted posi-
tion.
5. Check for proper operation. Axle set light is to deac-
tivate when the axle is retracted 0.625 inches (16
mm) maximum from fully extended.
Figure 3-1. Axle Limit Switch Adjustment