Volvo Penta D2-55, Workshop Manual

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38
Group 21 Short block
Inspecting the con rod
1. Check the con rods for cracking, straightness and
twist before considering changing the gudgeon pin
bush.
Discard the connecting rod if it is cracked, bent or
twisted.
Check the wear of the little end with a gudgeon
pin. If the clearance is correct, an oiled gudgeon
pin should slide slowly, due to its own weight,
through the bush.
2. Use a new gudgeon pin and measure con rod
straightness in a fixture. Max. deviation: 0.15 mm
for 100 mm measured length
3. Measure any con rod twist. Max. deviation: 0.20
mm for 100 mm measured length
Replacing con rod bushes
1. Press the old bush out.
2. Press the new bush in.
NOTE! Make sure that the oil hole in the bush lines up
with the drilling in the con rod. Draw a line across the
hole in the con rod and the bush, with a felt tip pen.
Check that the oil duct is open after pressing.
3. Broach the bush and measure the con rod with an
internal dial gauge.
4. Check the end float between the con rod and
crankshaft.
Change the con rod if the end float exceeds 0.035-
0.085 mm.
Also check the con rod bushes. Clearance be-
tween the gudgeon pin (A) and con rod bush (B),
refer to “Technical data”.