DOOR AS-ACCESS 3666450 - Caterpillar

Illustration 1 g02982598
(1) Priority Valve (2) Outlet to brake cooling motor (3) Oil filter (4) Pressure sensor (5) Auxiliary cooler (6) Rear axle cooling fan motor (7) Outlet to differential lube (8) Bypass valve (9) Final drive bypass manifold (10) Right final drive oil (11) Left final drive oil (12) Rear axle housing sump (13) Rear axle oil pump (14) Pump motor (15) Steering tank (16) Steering accumulator (17) Steering pump (18) Supply valveThe 793F has a continuous lubrication system for the rear axle. This system does not require the truck to be in motion in order to provide oil flow. This hydraulic system lubricates the bearings for the differential and bevel gear group and the bearings for the rear wheels. This hydraulic system also cools the bearings for the differential and bevel gear group and the bearings for the rear wheels. For the correct oil that should be used in the system, refer to the Operation and Maintenance Manual for your machine.The steering pump (17) supplies oil to the priority valve (1) . The brake ECM controls the supply valve (18) that is based on a temperature sensor that is mounted in the rear axle housing (12) . Oil flow is directed to the pump motor (14) when the supply solenoid valve (18) is OFF. Oil flow is blocked to the pump motor (14) when the supply solenoid valve (18) is ON.The pump motor (14) drives the rear axle oil pump (13) . The rear axle oil pump (13) sends oil to the rear axle oil filter (3) and to the final drive bypass manifold (9) . If the machine is equipped with an auxiliary cooler (5) , then oil will flow through the cooler before the bypass valve. The auxiliary cooler (5) reduces the temperature of the oil.The bypass solenoid valve (8) sends oil to the final drive and to the differential gear (7) or the bypass solenoid valve (8) will bypass the right final drive (10) and the left final drive (11) . This prevents the final drives from receiving too much oil under certain conditions.
Table 1
Rear Axle Lubrication Strategy    
    Supply solenoid valve     Bypass solenoid valve    
Rear Axle Oil Temperature     Cold
13° C (55.4° F) or less     Cool
15° to 56° C (59° to 132.8° F)     Hot
58° C (136.4° F) or greater     Cold
13° C (55.4° F) or less     Cool
15° to 56° C (59° to 132.8° F)     Hot
58° C (136.4° F) or greater    
Not Moving
0 km/h (0 mph)     OFF
ON after 5 min     OFF
ON after 5 min     OFF     ON     ON     OFF    
Moving
0 to 35 km/h (0 to 22 mph)     ON     OFF     OFF     ON     ON     OFF    
Moving Fast
> 35 km/h (> 22 mph)     ON     OFF     OFF     ON     ON     5 min ON
1 min OFF    
Gear Limit     3rd     4th     No                Note: