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Crankshaft bearing play, check (check crankshaft bearing play with a micrometer and internal measuring instrument)

Crankshaft bearing play, check (check crankshaft bearing play with a micrometer and internal measuring instrument)



1. Crankshaft removed.

Fit the crankshaft bearing cap together with the crankshaft bearing shell onto the engine block - tightening torque 50 Nm + 45° + 15°. The bolts can be used one more time for checking the crankshaft bearing play.

2. The average crankshaft bearing diameter is measured with an internal measuring instrument at positions I, II and III and is calculated.

Equation for calculating average big-end journal diameter: I + II + III
Crankshaft bearing diameter 3


Example:
I 54.972 mm
II 54.981 mm
III + 54.984 mm
164.937 mm divided by 3 = 54.979 mm


Average crankshaft bearing diameter is 54.979 mm.

3. The average crankshaft journal diameter is measured using a micrometer at positions I and II and then calculated.

Equation for calculating average big-end journal diameter: I + II
Crankshaft journal diameter 2


Example:
I 54.962 mm
II + 54.964 mm
109.926 mm divided by 2 = 54.963 mm


Average crankshaft bearing diameter is 54.963 mm.

4. The crankshaft journal play is calculated using the different diameters of the crankshaft bearing hole and the crankshaft journal.

Example:
Average crankshaft bearing diameter 54.979 mm
Average crankshaft journal diameter - 54.963 mm
0.016 mm


Permitted crankshaft bearing play: 0.005 to 0.059 mm