3-37. CRANKSHAFT REPAIR (Contd)
a. Cleaning (Contd)
If inspection or installation of crankshaft will be performed later, coat all journal surfaces
with a heavy film of OE/HDO 30 lubricating oil to prevent rust from forming.
Standard main bearing set
Clean with SD-3 solvent and
(1), seven retaining rings
(5), four thrust rings (3),
and two thrust ring pins (4)
Main bearings are provisioned as a set. If one main bearing half is not within specifications
or is found to be defective, discard entire main bearing set.
3. Standard main bearing
Inspect each main bearing
There are 14 main bearing
half for the following:
halves to a standard main bearing
set (1); inspect each half
a. Pits, scratches, or grooves.
Discard if pitted, scratched, or
Never remove any metal from bearing shells to change oil clearance. After operation, a
bearing shell that is fitted correctly will be gray. Light areas on shell indicate that metal is
touching metal without enough oil clearance. Dark areas on shell indicate that the
clearance is too large.
Wear limits for undersized bearing halves may be determined by adding the correct amount
(0.010 in. (0.254 mm), 0.020 in. (0.508 mm), and 0.030 in. (0.762 mm) to the minimum and
maximum dimension of a standard bearing.
b. Thickness of main bearing
Use a micrometer that has a
ball point. Minimum thickness is
0.123 in. (3.124 mm), maximum
thickness is 0.1238 in. (3.144 mm),
and wear limit is 0.1215 in.
4. Four thrust rings (3)
Measure thickness of each thrust
Prior to taking measurements,
ring (3) at different locations.
place crankshaft (2) on cylinder
block with corresponding bearing
halves and caps installed. A new
crankshaft (2) and new thrust ring
(3) will have an end clearance of
0.007-0.017 in. (0.179-0.432 mm).
If the clearance exceeds 0.022 in.
(0.559 mm), install oversize thrust
5. Two thrust ring pins (4)
Inspect for damage or wear.
Discard if damaged or worn.