LT230 Transfer Box: Description and Operation (Operation)
TRANSFER BOX
DESCRIPTION AND OPERATION
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Front output housing assembly
The front output shaft is supported in the front output
housing by a single bearing and is splined into the
differential front shaft.
The high/low cross shaft is located in a housing
bolted to the top of the output housing and is
connected to the high/low selector finger which
locates in a slot in the selector shaft.
The differential lock selector housing is also bolted
to the top of the front output housing, the selector
finger passes through the housing and locates in a
slot in the differential lock selector shaft. The shaft
passes through the selector fork which is located
beneath a plate bolted to the side of the output
housing. A spring loaded detent ball fitted in the
output housing locates in grooves in the shaft.
A differential lock warning lamp switch, operated by
movement of the selector fork and shaft is screwed
into the top of the output housing.
For certain markets, a low detect switch, operated
by the high/low selector is screwed into the cross
shaft housing on early boxes or into the side of the
output housing on later boxes.
Rear output housing assembly
The rear output shaft is supported in the rear output
housing by a single bearing and is splined into the
differential rear shaft. The output shaft also carries
the speedometer drive gear which meshes with the
driven gear located in the rear output housing.
Lubrication
Lubrication is by splash, oil filler/level plugs are
located in the main casing. An oil temperature switch
is also fitted for certain applications.
OPERATION
The gearbox input shaft transmits power to the
mainshaft input gear which is in constant mesh with
one of the intermediate gears. The intermediate
gears are in constant mesh with the high and low
range output gears running on the differential rear
shaft.
Power is transmitted to the output shafts by locking
either the high or low range gears to the differential
rear shaft. This is achieved by means of the high/low
selector fork, sleeve and splined hub.
The differential lock, when applied, prevents all
available power being transmitted to the road wheels
offering least resistance and is especially useful for
’off-road’ conditions. When selected, the selector
fork engages a dog clutch on the differential shaft
with a gear on the front output shaft; this locks the
differential and provide fixed drive thereby
transmitting equal power to both output shafts.