Dodge Dakota Sport 2001 Service Manual page 1067

9 - 38 ENGINE 2.5L
CRANKSHAFT MAIN BEARINGS (Continued)
(Fig. 40). Refer to Engine Specifications for the
proper clearance.
Fig. 40 Measuring Bearing Clearance with
Plastigage
1 - PLASTIGAGE SCALE
2 - COMPRESSED PLASTIGAGE
Plastigage should indicate the same clearance
across the entire width of the insert. If clearance var-
ies, it may indicate a tapered journal or foreign
material trapped behind the insert.
If the specified clearance is indicated and there are
no abnormal wear patterns, replacement of the bear-
ing inserts is not necessary. Remove the Plastigage
from the crankshaft journal and bearing insert.
Install bearings (Refer to 9 - ENGINE/ENGINE
BLOCK/CRANKSHAFT
INSTALLATION).
If the clearance exceeds specification, install a pair
of 0.025 mm (0.001 inch) undersize bearing inserts
and measure the clearance as described in the previ-
ous steps.
The clearance indicated with the 0.025 mm (0.001
inch) undersize insert pair installed will determine if
this insert size or some other combination will pro-
vide the specified clearance. FOR EXAMPLE: If the
clearance was 0.0762 mm (0.003 inch) originally, a
pair of 0.0254 mm (0.001 inch) undersize inserts
would reduce the clearance by 0.0254 mm (0.001
inch). The clearance would then be 0.0508 mm (0.002
inch) and within the specification. A 0.051 mm (0.002
inch) undersize bearing insert and a 0.0254 mm
(0.001 inch) undersize insert would reduce the origi-
nal clearance an additional 0.0127 mm (0.0005 inch).
The clearance would then be 0.0381 mm (0.0015
inch).
CAUTION: Never use a pair of inserts that differ
more than one bearing size as a pair.
MAIN BEARINGS
FOR EXAMPLE: DO NOT use a standard size
upper insert and a 0.051 mm (0.002 inch) undersize
lower insert.
If the clearance exceeds specification using a pair
of 0.051 mm (0.002 inch) undersize bearing inserts,
measure crankshaft
micrometer. If the journal diameter is correct, the
crankshaft bore in the cylinder block may be mis-
aligned, which requires cylinder block replacement or
machining to true bore.
If journals 1 through 5 diameters are less than
63.4517 mm (2.4981 inches), replace crankshaft or
grind crankshaft down to accept the appropriate
undersize bearing inserts.
Once the proper clearances have been obtained,
(Refer to 9 - ENGINE/ENGINE BLOCK/CRANK-
SHAFT MAIN BEARINGS - INSTALLATION).
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the spark plugs.
(3) Raise the vehicle.
(4) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL) and oil pump
(Refer to 9 - ENGINE/LUBRICATION/OIL PUMP -
REMOVAL).
(5) Remove only one main bearing cap and lower
insert at a time (Fig. 41).
-
Fig. 41 Removing Main Bearing Caps and Lower
1 - CONNECTING ROD JOURNAL
2 - MAIN BEARING CAPS
journal diameter with
Inserts
AN
a