ARMY TM 9-2815-260-24
AIR FORCE TO 38G1-126-2
MARINE CORPS TM 09244A/09245A-24
Remove capscrews (1) and washers (2) securing main bearing caps (3 and 4); remove main
Visually inspect condition of bearing inserts (5 and 6) as main bearing caps
are removed. Keep caps and inserts together and in correct order.
Check bearing (5 and 6) clearances as follows:
Place a strip of bearing gage (PLASTIGAGE) in the center of the main bearing cap about
three fourths of width of bearing.
Use oil on bearing gage to prevent smearing.
Install cap and tighten capscrews (1) to 100 lb-ft (135 Nm).
Remove cap and compare width of bearing gage with scale provided, to determine
clearance. Maximum permissible clearance is 0.0043 inch (0.109 mm).
Crankshaft is very heavy, do not attempt to remove crankshaft by hand.
Use proper lifting equipment.
Use of bearing gage will determine wear, but will not determine condition
of either bearing or journal.
Attach a nylon sling (or other suitable lifting sling) to journals of crankshaft (7).
An alternate method of attaching sling is to install a capscrew on both ends
of crankshaft and attach sling to screws.
Using proper lifting equipment, carefully raise crankshaft out of engine block.
Place crankshaft (7) on a clean flat surface and support journals with wooden blocks.
If bearings (5 and 6) are to be replaced, remove inserts from engine block. Otherwise, leave
bearing inserts in block until assembled inner diameter has been measured.
Using an arbor press and gear puller, pull gear (8) from crankshaft (7). Remove key (9) from