4-1. ENGINE MAINTENANCE (CONT)
d. Crankshaft and Main Bearings (Cont).
INSPECTION/REPAIR (SHEET 2 OF 3)
Check connecting rod journals for
wear using micrometer. If diame-
ters are smaller than 2.748
inches use undersize (0.002 inch)
inserts. If connecting rod jour-
nals are worn more than 0.002
inch, grind undersize to follow-
If one or more journals are to be
2.738 to 2.739
2.728 to 2.729
2.718 to 2.719
ground, grind all journals.
(6) Measure front and rear of each journal using micrometer, checking taper.
If taper exceeds 0.0005 inch, connecting rod journals must be ground.
Check connecting rod journals 90 degrees from first measurements for
out-of-roundness. If out-of-roundness exceeds 0.0005 inch, connecting rod
journals must be ground.
If crankshaft journals are reground, repeat steps (3) through (6) above.
(7) Using micrometer, measure thickness
of thrust washers (15). Replace
thrust washer if thickness is less
than 0.147 inch.
Inspect crankshaft gear (19) for
cracks, missing or broken teeth,
scoring, pits, or excessive wear.
Inspect main bearing liners (16 and
17) for cracks, scoring, pitting,
flaking, or signs of overheating.
Check liner back for bright spots.
(10) Check main bearing caps (12 thru 14) bore diameter as follows: