Crankshaft; Crank Pin Journal; Undersize Bearing - Westerbeke W70GA Service Manual

CRANKSHAFT
DISASSEMBLY /INSPECTION
CRANKSHAFT
1. Check the journals and pins for damage, scoring, or oil
hole clogging.
2. Set the crankshaft on V-blocks.
3. Check the crankshaft runout at the center journal. Replace
if
necessary
RUNOUT: 0.03mm (0.0012in) MAX.
TESTING
RUN·OUT
4. Measure each journal diameter in X and Y directions at
two
points.
MAIN JOURNAL
DIAMETER:
59.937 • 59.955mm (2.3597 • 2.3604in)
MINIMUM: 59.89mm (2.358in)
OUT OF ROUND: 0.05mm (0.0020in)
CRANK PIN JOURNAL
DIAMETER:
50.940 • 50.955mm (2.0055 - 2.0061in)
MINIMUM: 50.89mm (2.004in)
OUT OF ROUND: 0.05mm (0.0020in)
x
@>Y
REAR HOUSING
ASSEMBLY OIL SEAL
SLIDING SURFACE
~Ii
CR~NKfl_INS
MAIN JOURNALS
OIL PUMP BODY
ASSEMBLY OIL SEAL
SLIDING SURFACE
. ;
S. If the diameter is less than the minimum, grind the
journals to match undersize bearings.
UNDERSIZE BEARING: 0.25mm (0.010in)
0.50 MM (0.020 IN), 0.75mm (0.0301n)
MAIN JOURNAL DIAMETER UNDERSIZE MM(IN)
Bearing
Size Jaumal Diameter
0.25
No.1,2,4,5 59.693 • 59.711 (2.3501 • 2.3508)
Undersize
No.3 59.687. 59.705 (2.3499. 2.3506)
0.50 No.1,2,4,5 59.443. 59.461 (2.3404. 2.3410)
Undersize No.3
59.437 • 59.455 (2.3400 • 2.3407)
0.75
No.1,2,4,5 59.193. 59.211 (2.3304. 2.3311)
Undersize
No.3 59.187. 59.205 (2.3302. 2.3309)
CRANK PIN JOURNAL DIAMETER UNDERSIZE MM (IN)
22
· Bearing Size
Journal Diameter
0.25 Undersize
0.25 Undersize
0.25 Undersize
50.690. 50.705 (1.9957 • 1.9963)
50.440- 40.455 (1.9858 . 1.9864)
50.190. 50.205(1.9760·1.9766)
ALWAYS CHAMFER THE POINTS MARKED
WH_EN GRINDING THE JOUFJ!J(lLS AND PINS