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| Illustration 1 | g01902818 |
(1) Diverter valve (2) Solenoid valve (3) Pressure tap for pump oil | |
Diverter valve (1) for the final drive oil is located on the top of the rear axle housing.
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| Illustration 2 | g01902820 |
Bottom view of diverter valve (1) (3) Pressure tap for pump oil (4) Outlet port to the final drive oil filter (5) Outlet port to the differential (6) Inlet port from the gear pump for the rear axle oil | |
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| Illustration 3 | g01902823 |
ISO schematic for diverter valve (deactivated solenoid valve) (1) Diverter valve (2) Solenoid valve (3) Pressure tap for pump oil (4) Outlet port to the final drive oil filter (5) Outlet port to the differential (6) Inlet port from the gear pump for the rear axle oil (7) Poppet valve | |
Oil from the gear pump for the rear axle oil flows to inlet port (6) on diverter valve (1). When the temperature of the differential oil is above 60 °C (140 °F), solenoid valve (2) is deactivated. Pump pressure will flow to both ends of poppet valve (7). Since the surface area on the back side of poppet valve (7) is greater than the surface area on the front side of poppet valve (7), poppet valve (7) will be closed. The outlet port to the differential (5) will be blocked. Pump oil will flow past poppet valve (7) to the outlet port to the final drive oil filter (4) .
When the temperature of the differential oil is below 60 °C (140 °F), the Brake/Cooling ECM will activate solenoid valve (2). The pump pressure that was flowing behind poppet valve (7) will now dump to the sump for the differential through outlet port (5) to the differential. The pressure that is required for the oil to flow through the filter for the final drive is greater than the pressure that is required to move poppet valve (7). Poppet valve (7) now opens outlet port (5) to the differential. The outlet port to the final drive oil filter (4) is never blocked. However, the oil will flow more easily to the sump for the differential.
There are two advantages to diverting the oil away from the final drives:
- The final drives will not be overfilled with cold oil.
- The high oil level in the sump for the differential will cause the bevel gear to agitate the oil. This will cause rapid heating of the oil to the normal operating temperature of the system. Normal filtering of the oil and circulation of the oil to the final drives can then occur.