Oil flows from the transmission charging filter to the transmission control valve located on top of the transmission. Transmission charging oil flows from the transmission control valve and joins with the oil from the transmission lube section of the transmission pump.
Oil flows from the lube section of the transmission pump to the transmission lube filter.
Oil from the transmission lube filter and the transmission control valve flows through the transmission oil cooler. Oil flows from the transmission oil cooler to the transfer gears and the transmission to cool and lubricate the internal components.
Differential
Shown is the differential removed from the rear axle housing. The rear axle cooling and filter system starts with a rear axle pump (1) that is driven by the differential. Since the pump rotates only when the machine is moving, no oil flow is produced when the machine is stationary.
Cooling oil flow increases with ground speed to provide cooling when it is most needed.
The rear axle pump pulls oil from the bottom of the rear axle housing through a suction screen (2). Oil flows from the pump through a temperature and flow control valve located on top of the differential housing to a filter mounted on the rear of the axle housing. Oil then flows from the filter back to the valve located on top of the differential housing. Oil then flows from the valve to the rear wheel bearings and the differential bearings.
Oil flows through tubes (3) to the differential bearings.
The fiberglass shroud (4) reduces the temperature of the rear axle oil on long hauls by reducing the oil being splashed by the bevel gear.
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Oil flows from the pump through the large hose (1) to the rear axle temperature and flow control valve (2). A differential oil temperature sensor (3) and pressure sensor (4) are located on the temperature and flow control valve. The sensors provide input signals to the Brake ECM. The Brake ECM sends signals to the VIMS.
The differential temperature sensor input signal is used to warn the operator of a high rear axle oil temperature condition or to turn on the attachment rear axle cooling fan (if equipped).
The differential oil pressure sensor input signal is used to warn the operator of a HIGH or LOW rear axle oil pressure condition.
A HIGH oil temperature warning is provided if the temperature is above 118° C (244° F).
A LOW oil pressure warning is provided if the pressure is below35 kPa (5 psi) when the
differential oil temperature is above 52° C (125° F) and the ground speed is higher than 24 km/h (15 mph).
A HIGH oil pressure warning is provided if the pressure is above 690 kPa (100 psi) when the differential oil temperature is above 52° C (125° F).
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oil is cold. When the oil temperature is below 43° C (110° F), the valve is OPEN and allows oil to flow to the rear axle housing. When the oil temperature is above 43° C (110° F), the valve is CLOSED and all the oil flows through the filter to a flow control valve located in the temperature and flow control valve. The temperature and pressure control valve is also the system main relief valve. If the pressure exceeds 690 kPa (100 psi), the temperature and pressure control valve will open to prevent high oil pressure to the rear axle oil filter.
The flow control valve distributes the oil flow to the rear wheel bearings and the differential bearings.
Oil flows from the temperature and flow control valve to the differential oil filter mounted on the rear of the axle housing. Oil then flows from the filter back to the temperature and flow control valve. Some of the oil that flows from the temperature and flow control valve flows through the small supply hose (5) to the differential bearings.
The differential oil filter bypass switch (1) and the two rear axle oil level switches (2) (one behind differential filter) provide input signals to the Brake ECM. The Brake ECM sends signals to the VIMS.
The differential oil filter bypass switch signal is used to warn the operator when the differential oil filter is restricted.
The rear axle oil level switch input signals are used to warn the operator when the rear axle oil level is LOW.
When the truck is initially put into operation, a 1R0719 (40 micron) filter is installed. This filter removes the rust inhibitor used during manufacturing. The 40 micron filter should be changed after the first 50 hours of operation and replaced with a 4T3131 (13 micron) filter. The 13 micron filter should be changed every 500 hours.
A differential carrier thrust pin is located behind the small cover (3). The thrust pin prevents movement of the differential carrier during high thrust load conditions.
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Shown is a schematic of the rear axle oil cooling and filter system. The differential oil pump pulls oil from the bottom of the rear axle housing through a suction screen. Oil flows from the pump through a temperature and flow control valve located on top of the differential housing.
The temperature and pressure control valve, which is part of the temperature and flow control valve, prevents high oil pressure when the rear axle oil is cold. When the oil temperature is below 43° C (110° F), the valve is OPEN and allows oil to flow to the rear axle housing. When the oil temperature is above 43° C (110° F), the valve is CLOSED and all the oil flows through the differential oil filter and the oil cooler (if equipped) to a flow control valve, which is also part of the temperature and flow control valve.
The temperature and pressure control valve is also the system main relief valve. If the pressure exceeds 690 kPa (100 psi), the temperature and pressure control valve will open to prevent high oil pressure to the rear axle oil filter.
The flow control valve distributes the oil flow to the rear wheel bearings and the differential bearings. At high ground speeds, excess oil flow is diverted to the axle housing to prevent overfilling the wheel bearing and final drive compartments.
Oil Cooler Oil
Filter
Temperature / Pressure Control Valve
OIL COOLING AND FILTER SYSTEM
Temperature and
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