GMC Powertrain 4.3 L, Service Manual, Page: 185 / 196

Engine Marine/Industrial 4.3L 6-175
2000 Marine/Industrial
Lubrication
Engine Lubrication
Full pressure lubrication, through a full-flow oil filter is supplied
by a gear-type oil pump. Oil is drawn up through the oil pump
screen and passes through the pump to the oil filter. The oil
filter is full-flow paper element unit with an anti-drain back
valve. An oil filter bypass valve is used to ensure adequate
oil supply, in the event the filter becomes plugged or develops
excessive pressure drop. Filtered oil flows into the main
gallery and then to the camshaft, the balance shaft, the rear
bearing and the crankshaft bearings. The valve lifter oil
gallery supplies oil to the valve lifters. Oil flows from the
valve lifters through the hollow valve pushrods to the valve
rocker arms. Oil drains back to the crankcase through the
oil drain holes in the cylinder head. The camshaft timing
and piston pins are lubricated by oil splash.
Cleanliness and Care
•
Throughout this section, it should be understood
that proper cleaning and protection of machined
surfaces and friction areas is part of the repair
procedure. This is considered standard shop
practice even if not specifically stated.
•
When any internal engine parts are serviced, care
and cleanliness is important.
•
When components are removed for service, the
components should be marked, organized or
retained in a specific order for re-assembly.
chain is drip fed from the front camshaft bearing. The pistons