Crankshaft Main Bearing Journal Taper and Out-of-Round
WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
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NOTE: To prevent engine damage, the crankshaft must be reground or a new crankshaft installed if journals exceed maximum out-of-round and/or taper specifications.
Use a 75-100 mm (3-4 in) micrometer to measure the diameter of each main journal. Measure the journal at 2 points, 90 degrees apart. Measure and record readings for each of the 4 main journals. The difference between readings will be the main journal out-of-round value. For additional information, refer to SPECIFICATIONS .