Lull 1044C-54 Series II Service Manual - Manual (Page 302)

Frame Tilt and Oscillation
7-20 31200079
Boom Positioned Above 20° Below 40°
Fig. 7-13: Circuit Operation Above 20° Below 40°
(Ref. Fig. 7-13) The following describes the rear axle stabilizer circuit logic
when the boom is positioned above 20° below 40° elevation.
1. When the boom is above 20° and below 40°, the proximity switch (S2)
is sensing the boom, so the (S2) proximity switch closes. Proximity
switch (S1) is not sensing the boom, so it opens when boom is above
20°.
2. When the proximity switch (S1) is open, the Boom Over 20° relay is not
energized and power is directed to the coil of relay K13 of the
transmission logic (see Transmission Section 8). When K13 is
energized, the transmission is restricted to first and second gears only,
regardless of the gear selected with the transmission shifter.
3. Additionally, when the Boom Over 20° relay is not energized, Solenoid
Valve (SV1) is not energized, which restricts movement of the rear
stabilizer cylinder so that the frame may oscillate on the rear axle only
in a slow or restricted mode. The Boom Over 20° relay also illuminates
the Rear Oscillation Lock lamp in the instrument cluster.
4. The frame tilt is also restricted when Solenoid Valve (SV1) is not
energized.
MV0560
VALVE ON VALVE PLATE
REAR AXLE STABILIZER CONTROL
3-WAY SOLENOID VALVE ON
(ENERGIZED)
ON REAR STABILIZER CYLINDER
REAR AXLE STABILIZER VALVE
2-WAY SOLENOID VALVE ON
(ENERGIZED)
SOLENOID VALVE ON
REAR AXLE STABILIZER
CONTROL VALVE
(NOT ENERGIZED)
S2
BOOM ANGLE GREATER THAN 40 - OPEN
BOOM ANGLE LESS THAN 40 - CLOSED
BOOM ANGLE LESS THAN 20 - CLOSED
BOOM ANGLE GREATER THAN 20 - OPEN
S1
OVER 40°
BOOM
86 30
87 87A 85
B
A
SV1
OVER 20°
BOOM
86 30
87 87A 85
RELAY
RELAY
FROM
FUSE PANEL
+12 VOLTS
B
A
SV3
B
A
SV2
NOT ENERGIZED
ENERGIZED
TO RESTRICT
TRANSMISSION TO
1ST & 2ND GEARS
TO ENABLE FOOT
SWITCH AND TO
DISABLE
TRANSMISSION