a) Place the crankshaft on the prisms.
b) Using a dial indicator, check the runout of the crankshaft on the central main journal.
Nominal runout:
- K20A (models with type 3 rocker block) — 0.02 mm
- the rest - 0.03 mm
Maximum runout:
- K20A (models with type 3 rocker block) — 0.03 mm
- the rest - 0.04 mm
If the runout is greater than the maximum allowable, replace the crankshaft.
2. Check the connecting rod and main journals.
a) Using a micrometer, measure the diameter of each connecting rod and main journal in two mutually perpendicular planes, as shown in the figure.
Nominal neck diameter:
D17A:
- root - 54.976 - 55.000 mm
- connecting rod - 44.976 - 45.000 mm
D15A:
- root - 44.976 - 45.000 mm
- connecting rod - 41.976 - 42.000 mm
K20A:
root:
- №1,2,4,5 — 54.984 - 55.008 mm
- no.3 - 54,976 - 55,000 mm
connecting rod - 44.976 - 45.000 mm
If the diameter values are outside the limits specified in the table "Main and Connecting Rod Journal Diameters", regrind or replace the crankshaft.
b) Check the connecting rod and main journals for out-of-roundness as shown in the previous figure.
Nominal out-of-roundness:
- D15B, D17A — 0.0025 mm
- K20A - 0.005 mm
Maximum out-of-roundness:
- D15B, D17A — 0.005 mm
- K20A - 0.010 mm
If the out-of-roundness is greater than maximum, replace the crankshaft.