Jeep Cherokee 2000 Service Manual - page 1085
(4) Use a piston ring compressor to install the con-
necting rod and piston assemblies through the top of
the cylinder bores (Fig. 79).
(5) Ensure the arrow on the piston top points to
the front of the engine (Fig. 79).
(6) Raise the vehicle.
(7) Each bearing insert is fitted to its respective
journal to obtain the specified clearance between the
bearing and the journal. In production, the select fit
is obtained by using various-sized, color-coded bear-
ing inserts as listed in the Connecting Rod Bearing
Fitting Chart. The color code appears on the edge of
the bearing insert. The size is not stamped on inserts
used for production of engines.
(8) The rod journal is identified during the engine
production by a color-coded paint mark on the adja-
cent cheek or counterweight toward the flange (rear)
end of the crankshaft. The color codes used to indi-
cate journal sizes are listed in the Connecting Rod
Bearing Fitting Chart.
(9) When
required,
upper
and
lower
bearing
inserts of different sizes may be used as a pair (refer
to Connecting Rod Bearing Fitting Chart). A stan-
dard size insert is sometimes used in combination
with a 0.025 mm (0.001 inch) undersize insert to
reduce clearance 0.013 mm (0.0005 inch).
CAUTION: DO NOT intermix bearing caps. Each
connecting rod and bearing cap are stamped with
the cylinder number. The stamp is located on a
machined surface adjacent to the oil squirt hole
that faces the camshaft side of the cylinder block.
(10) Install the connecting rod bearing caps and
inserts in the same positions as removed.
CAUTION: Verify that the oil squirt holes in the
rods face the camshaft and that the arrows on the
pistons face the front of the engine.
(11) Install main bearing cap brace (Fig. 76).
Tighten nuts to 47 N·m (35 ft. lbs.).
(12) Install the oil pan and gaskets as outlined in
the installation procedure.
(13) Lower the vehicle.
(14) Install the engine cylinder head, push rods,
rocker arms, bridges, pivots and engine cylinder head
cover.
(15) Fill the crankcase with engine oil.
CRANKSHAFT OIL SEALS—REAR
The crankshaft rear main bearing oil seal consists
of two half pieces of viton with a single lip that effec-
tively seals the rear of the crankshaft. Replace the
upper and lower seal halves as a unit to ensure leak-
free operation.
REMOVAL
(1) Remove transmission inspection cover.
(2) Remove oil pan. Refer to procedure in this sec-
tion
(3) Remove main bearing cap brace.
(4) Remove rear main bearing cap (No.7).
(5) Push upper seal out of the groove. Ensure that
the crankshaft and seal groove are not damaged.
(6) Remove lower half of the seal from the bearing
cap.
INSTALLATION
(1) Wipe the seal surface area of the crankshaft
until it is clean.
(2) Apply a thin coat of engine oil.
(3) Coat lip of the seal with engine oil.
(4) Carefully position the upper seal into the
groove in the cylinder block. The lip of the seal faces
toward the front of the engine.
(5) Apply Mopar
t
Gasket Maker sealer on both
sides of cylinder block as shown in (Fig. 80). The dab
of sealer should be 3 mm (0.125 in.) in diameter.
(6) Apply Mopar
t
Gasket Maker on the rear bear-
ing cap (Fig. 80). The bead should be 2.3 mm (0.09
in.) in diameter. DO NOT apply sealer to the lip of
the seal.
(7) Position the lower seal into the bearing cap
recess and seat it firmly. Be sure the seal is flush
with the cylinder block pan rail.
(8) Coat the outer curved surface of the lower seal
with soap and the lip of the seal with engine oil.
(9) Install the rear main bearing cap. DO NOT
strike the cap more than twice for proper engage-
ment.
(10) Tighten all main bearing bolts to 108 N·m (80
ft. lbs.) torque.
(11) Install the main bearing cap brace. Tighten
nuts to 47 N·m (35 ft. lbs.).
(12) Install the oil pan gasket and oil pan. Tighten
1/4 – 20 screws to 14 N·m (120 in. lbs.). Tighten 5/16
– 18 screws to 18 N·m (156 in. lbs.)
Fig. 79 Rod and Piston Assembly Installation
9 - 110
4.0L ENGINE
XJ
REMOVAL AND INSTALLATION (Continued)