Build Date Code; Build Date Code Location - Jeep Wrangler 1997 Manual

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DESCRIPTION AND OPERATION (Continued)
The crankshaft rotation is clockwise, when viewed
from the front of the engine . The crankshaft rotates
within five main bearings and the camshaft rotates
within four bearings .
BUILD DATE CODE
The engine Build Date Code is located on a
machined surface on the right side of the cylinder
block between the No.3 and No .4 cylinders (Fig. 2) .
Fig. 2 Build Date Code Location
The digits of the code identify :
" 1st Digit-The year (6 = 1996).
" 2nd & 3rd Digits-The month (01 - 12) .
" 4th & 5th Digits-The engine type/fuel system/
compression ratio (HX = A 2.5 liter (150 CID) 9.2:1
compression ratio engine with a multi-point fuel
injection system) .
" 6th & 7th Digits-The day of engine build (01 -
31) .
FOR EXAMPLE : Code * 601HX23 * identifies a
2 .5 liter (150 CID) engine with a multi-point fuel
2 .5L ENGINE
9 - 1 7
injection system, 9.2 :1 compression ratio and built on
January 23, 1996 .
LUBRICATION SYSTEM
A gear-type positive displacement
pump is
mounted at the underside of the block opposite the
No. 4 main bearing. The pump draws oil through the
screen and inlet tube from the sump at the rear of
the oil pan . The oil is driven between the drive and
idler gears and pump body, then forced through the
outlet to the block. An oil gallery in the block chan-
nels the oil to the inlet side of the full flow oil filter.
After passing through the filter element, the oil
passes from the center outlet of the filter through an
oil gallery that channels the oil up to the main gal-
lery which extends the entire length of the block .
Galleries extend downward from the main oil gal-
lery to the upper shell of each main bearing . The
crankshaft is drilled internally to pass oil from the
main bearing journals (except number 4 main bear-
ing journal) to the connecting rod journals . Each con-
necting rod bearing cap has a small squirt hole, oil
passes through the squirt hole and is thrown off as
the rod rotates . This oil throwoff lubricates the cam-
shaft lobes, distributor drive gear, cylinder walls, and
piston pins.
The hydraulic valve tappets receive oil directly
from the main oil gallery. Oil is provided to the cam-
shaft bearing through galleries . The front camshaft
bearing journal passes oil through the camshaft
sprocket to the timing chain. Oil drains back to the
oil pan under the number one main bearing cap.
The oil supply for the rocker arms and bridged
pivot assemblies is provided by the hydraulic valve
tappets which pass oil through hollow push rods to a
hole in the corresponding rocker arm. Oil from the
rocker arm lubricates the valve train components,
then passes down through the push rod guide holes
in the cylinder head past the valve tappet area, and
returns to the oil pan .