Crankshaft; Checking Crankshaft Dimensions - Kohler KD 425-2 Workshop Manual

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KD 425-2 Workshop Manual_cod. ED0053029360_1° ed_ rev. 00
2. Position the calibrated pin on two prisms arranged on a check
surface.
3. Use a dial gauge to check that the discrepancy between readings
at the ends of the calibrated pin is no more than 0.05 mm; should
deformation exceed this value (max. 0.10mm) the connecting rod
must be straightened.
This operation is performed by placing the connecting rod on a
parallel surface and applying slight pressure mid-way along the
convex side of the stem (fig.24).

Crankshaft

Whenever the engine is dismantled, particularly for the replacement
of cylinders and pistons due to wear caused by the aspiration of dust,
it is good practice to check the condition of the crankshaft.
1. Remove the plugs "A" from the oil passages (fig.25).
2. Use an appropriately shaped steel punch to clean the inside of
the oil passages and the collection traps. If the deposits are parti-
cularly resistant, immerse the whole crankshaft in petrol or paraf-
fin before proceeding with the operations.
3. When the oil passages and traps have been throughly cleaned,
close the openings with new plugs (fig.26).

Checking crankshaft dimensions

Once the crankshaft has been thoroughly cleaned, use a micrometer
to check the wear and ovality of the main journals and crank journals
across two sections at right angles to each other (fig.27).
If wear exceeds 0.08 mm (fig.28) grind the crankshaft to the dimen-
sions shown in the table:
Dimensions
STD mm
45,005
A - B - D
÷
45,015
39,994
C
÷
40,010
Undersize bearing bushes are already available at the necessary si-
zes without requiring any adjustment by boring.
CHECKS AND OVERHAUL
-0,25 mm -0,50 mm
44,755 44,505
÷ ÷
44,765 44,515
39,744 39,494
÷ ÷
39,760 39,510
X
-0,75 mm
44,255
÷
44,265
39,244
÷
39,260
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