Final Drive Oil Cooling System; Principle Of Operation - Winnebago 1987-1989 LeSharo Service Manual

FINAL DRIVE OIL COOLING SYSTEM
All 1987 and later vehicles are equipped with a final
drive oil cooler.
The final drive cooling system consists of seven main
components:
1. an oil-to-water cooler incorporated into the
radiator
2. an electrical oil pump
3. an in-line oil filter assembly
4. a final drive oil thermoswitch
5. oil lines
6. a timer-relay
7. a circuit breaker
Principle of Operation
1. When the fi nal d rive oi I reaches 248°F (120°C)
the thermoswitch, mounted into the lower front
of the final drive case, triggers a timer-relay
which turns on the electric oil pump. (Since the
electrical components are connected directly to
the battery through the alternator, this can take
place even while the ignition key is off.)
2. The timer-relay allows the pump to operate for
a minimum cycle of 3 minutes after starting. The
timer-relay is mounted on the EGR Control
bracket behind the driver side headlight. (See
Figure 1.)
3. The oil is circulated from the bottom of the final
drive case to an in-line oil filter* and the pump
assembly. The filter and pump are located on
the driver side frame rail beside the engine.
*The oil filter is designed for the life of the
vehicle-unless final drive or pump failure occurs.
In this case, the system must be flushed and the
filter replaced.
4. The oil travels from the pump to an oil cooler
incorporated into the radiator and returns to the
final drive case. (See Figure 2.)
Figure 1
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'Pipe (A) must always slope upward from
pump inlet to prevent loss of prime.
Figure 2
Oil Cooler
F7-24