Crankshaft Bearing Clearance, Check (Determine
Bearing Clearance with Micrometer and Inside Micrometer)
The crankshaft is removed.
Install
Install crankshaft bearing cap with crankshaft bearing shell at
cylinder block – tightening torque 50 Nm / 37 lbf. ft. +
45° + 15°. To check the crankshaft bearing play, bolt can
be reused.
Measure
The average crankshaft bearing diameter is measured using an
inside micro-meter at points I, II and III and then calculated.
Formula for calculating the average con-rod bearing
diameter:
|
I + II + III
|
|
3
|
Example:
|
I
|
|
57.972 mm
|
|
II
|
|
57.981 mm
|
|
III
|
+
|
57.984 mm
|
|
|
|
173.937 mm
|
divided by 3 = 57.979 mm
|
The average con-rod bearing diameter is 57.979 mm.
|
|
Measure
The crankshaft journal diameter is measured with a micrometer at
points I and II and then calculated.
Formula for calculating the average con-rod bearing
diameter:
|
I + II
|
|
2
|
Example:
|
|
|
|
I
|
|
57.962 mm
|
|
II
|
+
|
57.964 mm
|
|
|
|
115.926 mm
|
divided by 2 = 57.963 mm
|
The average crankshaft journal diameter is 57.963 mm.
|
|
Measure
The crankshaft clearance is calculated
from the difference in diameter between the crankshaft bearing bore
and crankshaft journal.
Example:
|
|
|
Average crankshaft bearing diameter
|
|
57.979 mm
|
Average crankshaft journal diameter
|
–
|
57.963 mm
|
|
|
0.016 mm
|
Permissible crankshaft bearing play: 0.015 to 0.043 mm.
|