ARMY TM 9-2815-256-24
AIR FORCE TO 38G1-96-2
MARINE CORPS TM 2815-24/5
NOTE
Use bearing gage (PLASTIGAGEPR1) as directed by manufacturer. Remember, use of bearing gage
will determine bearing to journal clearance, but will not indicate the condition of either surface.
(1)
Remove connecting rod cap. Place a piece of bearing gage (PLASTIGAGEPR1) in center of bearing.
Install cap and initially tighten old capscrews to 41 ft-lbs (56 Nm). Tighten capscrews an additional 90 to
100 degrees, refer to paragraph 3-49.3.i for Torque-Turn Method for proper torque.
(2)
Remove cap and compare width of bearing gage with scale provided on side of package to determine
clearance. Maximum permissible clearance is 0.0062 inch (0.16 mm).
b.
Inspect and measure connecting rod bearing as follows:
CAUTION
Never use new connecting rod capscrews when checking rod bearing ID. Use new capscrews only
for final assembly of connecting rods.
(1)
With crankshaft removed, measure connecting rod journal OD at several points. OD should be 2.748 to
2.749 inches (69.80 to 69.82 mm).
(2)
Install connecting rod cap on rod with bearings using old capscrews.
(3)
Install rod capscrews and initially tighten to 41 ft-lbs (56 Nm). Tighten capscrews an. additional 90 to 100
degrees, refer to paragraph 3-49.3.i for Torque-Turn Method for proper torque.
(4)
Using an inside micrometer, measure assembled ID of rod bearing. ID should be 2.750 to 2.752 inches
(69.85 to 69.90 mm)
(5)
Subtract OD of crankshaft journals from ID of rod bearings to obtain oil clearance. Oil clearance for new
parts should be 0.0012 to 0.004 inch (0.03 to 0.10 mm). Maximum serviceable clearance is 0.0062 inch
(0.16 mm).
(6)
Inspect connecting rod bearings for wear or damage. If bearings are worn or are out of specification,
replace both connecting rod bearings.
c.
Inspect rod and cap as follows:
(1)
Inspect rod and cap for wear or damage, such as chips or cracks in joint area.
(2)
Inspect in and around capscrew holes in cap. If any defects are found, replace rod and cap.
(3)
Carefully clamp rod in a soft-jawed vise (cap end upward).
CAUTION
Never use new connecting rod capscrews when checking rod bore ID. Use new capscrews only for
final engine assembly.
(4)
Install cap without bearing inserts.
(5)
Initially tighten capscrews to 41 ft-lbs (56 Nm). Tighten capscrews an additional 90 to 100 degrees, refer to
paragraph 3-49.3.i for Torque-Turn Method for proper torque.
(6)
Using an inside micrometer, measure rod bore at center of bore and record measurements as follows:
(a)
At right angle to rod/cap joint.
(b)
At 45 degrees left of measurement step (a).
3-202
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