Dodge 2001 Ram 1500 Owner's Manual page 1237

9 - 90 ENGINE 5.2L
CRANKSHAFT MAIN
BEARINGS
DESCRIPTION
Main bearings (Fig. 25) are located in the cylinder
block. One half of the main bearing is located in the
crankshaft main bore the other half of the matching
bearing is located in the main bearing cap. there are
five main bearings. Number three main bearing is
flanged, this flange controls crankshaft thrust.
Fig. 25 Main Bearing Orientation
OPERATION
The main bearings encircle the crankshaft main
bearing journals, this aligns the crankshaft to the
centerline of the engine and allows the crankshaft to
turn without wobbling or shaking therefore eliminat-
ing vibration. The main bearings are available in
standard and undersizes.
STANDARD PROCEDURE—CRANKSHAFT MAIN
BEARING FITTING
Bearing caps are not interchangeable and should
be marked at removal to ensure correct assembly.
Upper and lower bearing halves are NOT inter-
changeable. Lower main bearing halves of No.2 and 4
are interchangeable.
Upper and lower No.3 bearing halves are flanged
to carry the crankshaft thrust loads. They are NOT
interchangeable with any other bearing halves in the
engine (Fig. 26). Bearing shells are available in stan-
dard and the following undersizes: Never install an
undersize bearing that will reduce clearance below
specifications.
Main Bearing Undersize Availability List
• 0.25 mm (0.001 inch)
• 0.051 mm (0.002 inch)
• 0.076 mm (0.003 inch)
• 0.254 mm (0.010 inch)
• 0.305 mm (0.012 inch)
Fig. 26 Main Bearing
REMOVAL
(1) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(2) Remove the oil pump from the rear main bear-
ing cap (Refer to 9 - ENGINE/LUBRICATION/OIL
PUMP - REMOVAL).
(3) Identify bearing caps before removal. Remove
bearing caps one at a time.
(4) Remove upper half of bearing by inserting
Crankshaft Main Bearing Remover/Installer Tool
C-3059 into the oil hole of crankshaft (Fig. 27).
(5) Slowly rotate crankshaft clockwise, forcing out
upper half of bearing shell.
INSTALLATION
Only one main bearing should be selectively fitted
while all other main bearing caps are properly tight-
ened. All bearing capbolts removed during service
procedures are to be cleaned and oiled before instal-
lation.
When installing a new upper bearing shell, slightly
chamfer the sharp edges from the plain side.
(1) Start bearing in place, and insert Crankshaft
Main Bearing Remover/Installer Tool C-3059 into oil
hole of crankshaft (Fig. 27).
(2) Slowly rotate crankshaft counterclockwise slid-
ing the bearing into position. Remove Tool C-3059.
(3) Install the bearing caps. Clean and oil the
bolts. Tighten the capbolts to 115 N·m (85 ft. lbs.)
torque.
(4) Install the oil pump (Refer to 9 - ENGINE/LU-
BRICATION/OIL PUMP - INSTALLATION).
BR/BE