Dodge Dakota Sport 2001 Service Manual page 1122

AN
CRANKSHAFT (Continued)
Fig. 27 Sealant Application to Bearing Cap
1 - MOPAR SILICONE RUBBER ADHESIVE SEALANT SLOTS
2 - LOCTITE 515 (OR EQUIVALENT)
3 - CAP ALIGNMENT SLOT
4 - REAR MAIN BEARING CAP
(13) Install new rear oil seal (Refer to 9 -
ENGINE/ENGINE
SEAL - REAR - INSTALLATION).
Fig. 28 Apply Sealant to Bearing Cap-to-Block Joint
1 - MOPAR GEN II SILICONE RUBBER ADHESIVE SEALANT
NOZZLE TIP
2 - SEALANT APPLIED
3 - CYLINDER BLOCK
4 - REAR MAIN BEARING CAP
CRANKSHAFT MAIN
BEARINGS
DESCRIPTION
Main bearings (Fig. 29) 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
BLOCK/CRANKSHAFT
four main bearings. Number two main bearing is
flanged, this flange controls crankshaft thrust.
Fig. 29 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.
OIL
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. 1 and
3 are interchangeable.
Upper and lower No. 2 bearing halves are flanged
to carry the crankshaft thrust loads. They are NOT
interchangeable with any other bearing halves in the
engine (Fig. 30). Bearing shells are available in stan-
dard and the following undersizes: 0.25 mm (0.001
in.), 0.051 mm (0.002 in.), 0.076 mm (0.003 in.), 0.254
mm (0.010 in.) and 0.305 mm (0.012 in.). Never
install an undersize bearing that will reduce clear-
ance below specifications.
Fig. 30 Main Bearing Identification
ENGINE 3.9L 9 - 93