Dodge RAM 1500 1998 Owner's Manual page 1374

DR
LUBRICATION (Continued)
The camshaft exhaust valve lobes and rocker arms
are lubricated through a small hole in the rocker
arm; oil flows through the lash adjuster then through
the rocker arm and onto the camshaft lobe. Due to
the orentation of the rocker arm, the camshaft intake
lobes are not lubed in the same manner as the
exhaust lobes. The intake lobes are lubed through
internal passages in the camshaft. Oil flows through
Oil Pickup Tube
Block Main Oil Gallery
Crankshaft Main Journals
Crankshaft Number One Main Journal
Left Cylinder Head
Right Cylinder Head
* The cylinder head gaskets have an oil restricter to control oil flow to the cylinder heads.
ENGINE LUBRICATION FLOW CHART—CYLINDER HEADS: TABLE 2
Cylinder Head Oil Port (in bolt hole)
Main Oil Gallery (drilled through head from rear to
Base of Camshaft Towers
Lash Adjuster Towers
** The number three camshaft bearing journal feeds oil into the hollow camshaft tubes. Oil is routed to the intake
lobes, which have oil passages drilled into them to lubricate the rocker arms.
ENGINE LUBRICATION FLOW CHART—BLOCK: TABLE 1
FROM
Oil Pump
Oil Filter
FROM
front)
a bore in the number 3 camshaft bearing bore, and
as the camshaft turns, a hole in the camshaft aligns
with the hole in the camshaft bore allowing engine
oil to enter the camshaft tube. The oil then exits
through 1.6mm (0.063 in.) holes drilled into the
intake lobes, lubricating the lobes and the rocker
arms.
Block Main Oil Gallery
1. Crankshaft Main Journal
2. Left Cylinder Head*
3. Right Cylinder Head*
Crankshaft Rod Journals
1.Front Timing Chain Idler Shaft
2.Both Secondary Chain Tensioners
See Table 2
See Table 2
Diagonal Cross Drilling to Main Oil Gallery
1. Base of Camshaft Towers
2. Lash Adjuster Towers
Vertical Drilling Through Tower to Camshaft Bearings**
Diagonal Drillings to Hydraulic Lash Adjuster Pockets
ENGINE - 4.7L
TO
Oil Pump
Oil Filter
TO
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