ENGINE AR-COMPL 20R0768 - Caterpillar

Illustration 1 g01087263
Lubrication system schematic
(1) Upper rear idler bearing
(2) Oil passage for the rear housing
(3) Middle rear idler bearing
(4) Rear oil line
(5) Lower rear idler
(6) Oil passage to rocker arms and camshaft bearings
(7) Oil passage to the heads
(8) Oil gallery in the head
(9) Camshaft bearings
(10) Shaft bearing for the live idler
(11) Connecting rod with drilled oil passage
(12) External oil line to rear gear train
(13) Piston cooling jets
(14) Lower front idler gear bearing
(15) Main bearings
(16) Right side turbocharger oil supply line
(17) Left side turbocharger oil supply line
(18) Auxiliary oil filter (if equipped)
(19) Main oil gallery
(20) Extension for the oil gallery
(21) Oil filter bypass valve
(22) Oil cooler bypass valve
(23) Oil cooler
(24) Oil pump
(25) Oil pump bypass valve
(26) Oil pan
(27) Oil filterThe oil pump (24) is mounted to the bottom of the cylinder block within the oil pan (26). The oil pump (24) pulls oil from the oil pan (26). The oil then flows through a passage to the oil cooler (23). Oil then flows through the oil filters (27). The oil can flow into the main oil gallery (19) from the right side or the left side of the block. The location of the incoming oil supply depends on the location of the oil filters which can be located on either side of the block. The oil then flows through a set of cross-drilled holes to the opposite side oil gallery.The main oil gallery (19) distributes oil to the following components: the crankshaft main bearings (15), the piston cooling jets (13), the extension of the oil gallery (20), the turbocharger oil supply line (16), the turbocharger oil supply line (17), and the live front idler gear bearings (10). The main oil gallery (19) also distributes oil to the rear accessory drives through an external oil line (12).Oil enters the crankshaft through holes in the bearing surfaces (journals) for the main bearing (15). Passages connect the bearing surface (journal) for the main bearing (15) with the bearing surface (journal) for the connecting rod (11). The oil flows upward through a drilled passage in the connecting rod to the piston pin bearing.The extension for the oil gallery (20) is located in the front right corner of the engine block. The extension for the oil gallery (20) supplies oil to the lower front idler gear bearing (14).The oil flows to the live front idler gear bearing (10) and around bearing (10) to the oil passage for the cylinder head (7). The oil then flows to the oil gallery in the cylinder head (8) and the oil flows to the oil passage (6) for the camshaft bearings (9) and the rocker arms.The oil for the lower rear idler bearing (5) is feed from a passage that is connected to the last rear main crankshaft bearing (15). Oil is also fed from the rear main bearing to the rear oil line (4) and to the oil passage in the rear housing (2) for the middle rear idler gear bearing (3) and the upper rear idler gear