Assembly Of Crank Connecting Rod Mechanism - Chery QQ Service Manual

Chery QQ Service Manual
4.2.7 Inspect the clearance between the piston and
cylinder wall
4.2.7.1 Measure the inner diameter of the cylinder and
the outer diameter of the piston at the positions as
indicated in the right figure. If the measurement results
exceed the limit, replace the piston or cylinder.
Standard value: 0.018～0.030
Limit: 0.10
[Reference] The clearance between the piston and cylinder
bore is controlled by the difference between the minimum
inside diameter of piston hole and the maximum outer
diameter of piston.
4.2.7.2 After replacing the piston or the cylinder body,
confirm the clearance again
Standard value: 0.018～0.030
4.3 Crankshaft
4.3.1 Inspect the proper alignment of the main axle
diameter.
4.3.1.1 Measure the proper alignment with a dial gauge,
if the proper alignment is beyond the limit, replace the
crankshaft.
Limit: 0.03mm
Notice: The bending value should be equal to
one-second the run-out value of crankshaft rotating one
circle.
4.3.2 Inspect the crankshaft for the abrasion.
4.3.2.1 Measure the connecting rod journal at the
positions indicated in the left figure with a microcaliper,
and figure out the roundness and cylindricity.
Limit: 0.005mm
4.3.2.2 Measure the connecting rod journal at the
positions indicated in the right figure with a microcaliper,
and figure out the roundness and cylindricity.
Limit: 0.004mm
5 Assembly of Crank Connecting Rod
mechanism
5.1 Assembly of the piston connecting rod
Mechanical Part of SQR 472Engine
Measurement
position of piston
Inner Diameter
46
Measurement position of piston
Outer Diameter