• When checking #4 main bearing shim #3 main
bearing.
NOTE: REMOVE ALL SHIMS BEFORE REASSEM-
BLING ENGINE
ALTERNATIVE METHOD
The weight of the crankshaft can be supported by a
jack under the counterweight adjacent to the bearing
being checked.
PLASTIGAGE PROCEDURE
(1)
Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(2) Place a piece of Plastigage across the entire
width of the bearing shell in the cap approximately
6.35 mm (1/4 in.) off center and away from the oil
holes (Fig. 1). (In addition, suspected areas can be
checked by placing the Plastigage in the suspected
area). Torque the bearing cap bolts of the bearing
being checked to the proper specifications.
(3)
Remove the bearing cap and compare the
width of the flattened Plastigage (Fig. 2) with the
metric scale provided on the package. Locate the
band closest to the same width. This band shows the
amount of clearance in thousandths of a millimeter.
Differences in readings between the ends indicate the
amount of taper present. Record all readings taken.
Refer to Engine Specifications. Plastigage gener-
ally is accompanied by two scales. One scale is
in inches, the other is a metric scale.
NOTE:
Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
CONNECTING ROD BEARING CLEARANCE
Engine connecting rod bearing clearances can be
determined by use of Plastigage or equivalent. The
following is the recommended procedure for the use
of Plastigage:
(1) Rotate the crankshaft until the connecting rod
to be checked is at the bottom of its stroke.
(2)
Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(3) Place a piece of Plastigage across the entire
width of the bearing shell in the bearing cap approx-
imately 6.35 mm (1/4 in.) off center and away from
the oil hole (Fig. 1). In addition, suspect areas can be
checked by placing plastigage in the suspect area.
(4) Assemble the rod cap with Plastigage in place.
Tighten the rod cap to the specified torque. Do not
rotate the crankshaft while assembling the cap
or the Plastigage may be smeared, giving inac-
curate results.
(5)
Remove the bearing cap and compare the
width of the flattened Plastigage (Fig. 2) with the
scale provided on the package. Locate the band clos-
est to the same width. This band indicates the
amount of oil clearance. Differences in readings
between the ends indicate the amount of taper
present. Record all readings taken. Refer to Engine
Specifications. Plastigage generally is accompa-
nied by two scales. One scale is in inches, the
other is a metric scale. If the bearing clearance
exceeds 0.076 mm (0.003 in.) replace bearing.
NOTE:
Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
CHECKING ENGINE OIL LEVEL
The best time to check engine oil level is after it
has sat overnight, or if the engine has been running,
allow the engine to be shut off for at least 5 minutes
before checking oil level.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil level
reading. Add only when the level is at or below the
ADD mark.
ENGINE OIL SERVICE
WARNING:
NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY. CONTACT YOUR DEALER OR GOVERN-
MENT AGENCY FOR LOCATION OF COLLECTION
CENTER IN YOUR AREA.
Fig. 2 Clearance Measurement
300M
ENGINE
9 - 3
GENERAL INFORMATION (Continued)