Lull 6K Service Manual - Manual (Page 568)

Transmission
8-20 Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K
Rear Oscillation Lock Proximity Switch and Relay
General
Fig. 8-9: Rear Oscillation Lock Proximity Switch
(Ref. Fig. 8-9) The rear oscillation lock proximity switch is located at the
rear left side of the transfer carriage. This switch senses if the boom
elevation is above or below 40°.
When the boom elevation is below 40°, the proximity switch is closed and
energizes the proximity switch relay (R1). As long as the proximity switch
relay (R1) remains energized (with the park brake off, the declutch switch
in the “OFF” position, and the service brake not applied), the transmission
will engage when the direction/speed range selector is shifted to forward or
reverse.
When the boom elevation exceeds 40°, the proximity switch opens.
Machines w/ DW-2
Shifter For machines equipped with a DW-2 shifter, the open proximity switch
stops the signal energizing the proximity switch relay (R1). The proximity
switch relay relaxes and routes a signal from the fuse panel to the EST-19
microprocessor. This signal enables the EST-19 microprocessor to stop
signals to the transmission solenoids that engage forward/reverse and this
declutches the transmission.
Machines w/ DW-3
Shifter For machines equipped with a DW-3 shifter, the open proximity switch
stops the signal energizing the proximity switch relay (R1). The proximity
switch relay relaxes and routes a signal from the fuse panel to the
transmission declutch relay, energizing it. This stops power to the DW-3
shifter, preventing the shifter from sending the signals to the transmission
solenoids that engage forward/reverse and this declutches the
transmission.
A symptom of a failed proximity switch is a transmission that will not go into
forward or reverse (loss of forward and reverse clutch packs). If this
happens, check the proximity switch integrity (see below).
j1074
Inner Jam Nut
Outer Jam Nut
Proximity Switch
Connection Wire
Wire Harness