CRANKSHAFT MAIN BEARING – FITTING
MAIN BEARING JOURNAL DIAMETER (CRANKSHAFT REMOVED)
Crankshaft removed from the cylinder block.
Clean the oil off the main bearing journal.
Determine the maximum diameter of the journal with a micrometer. Measure at two locations 90ยฐ apart at each end
of the journal.
The maximum allowable taper is 0.008mm (0.0004 inch.) and maximum out of round is 0.005mm (0.0002 inch).
Compare the measured diameter with the journal diameter specification (Main Bearing Fitting Chart). Select inserts
required to obtain the specified bearing-to-journal clearance.
CRANKSHAFT MAIN BEARING SELECTION
The main bearings are “select fit” to achieve proper oil clearances. For main bearing selection, the crankshaft counter weight has grade identification marks stamped into it. These marks are read from left to right, corresponding with
journal number 1, 2, 3, 4 and 5.
NOTE: Service main bearings are coded. These codes identify what size (grade) the bearing is.
MAIN BEARING SELECTION CHART – 5.7L
