Chery T21 2014 Service Manual page 511

6. Check piston ring end gap.
a. Using a piston, push the piston ring from the top of
cylinder to a place that is 45 mm from the top of
cylinder bore.
b. Using a feeler gauge, measure the end gap.
Measurement Item
First Ring
Piston Ring End
Gap
Second Ring
If piston ring end gap is not within the specified range,
replace the piston ring with a new one.
If end gap is still not within the specified range after
replacement, replace the engine block.
7. Check diameter of crankshaft main journal.
a. Using a micrometer, measure the main journal
diameter. Measure again after rotating the crankshaft
for 90°.
Measurement Item
Crankshaft Main Journal Diameter
If crankshaft main journal diameter is not within the
specified range, replace the main bearing shells with
new ones, and check radial clearance of crankshaft
(See page 07-90).
If radial clearance of the main bearing shell is still not
within the specified range after replacement, replace
the crankshaft.
b. Calculate the crankshaft cylindricity by measured values (measured area is shown in the illustration).
Roundness calculation method (for general measurement):
Measure the diameter twice on the same cross section, and the roundness is half of the difference
between maximum and minimum values.
Roundness = (maximum diameter - minimum diameter)/2
As shown in the illustration, measure the diameter twice in different directions on two cross sections
separately to obtain four values. The cylindricity is the half of the difference between maximum and
minimum values among the four values.
Cylindricity = (maximum diameter - minimum diameter)/2
Crankshaft Main Journal
Chery Automobile Co., Ltd.
Specification
(mm)
0.2 - 0.4
0.4 - 0.6
Specification
(mm)
0
54
-0.019
Measurement Item
Cylindricity
Roundness
07 - SQR484F ENGINE MECHANICAL
45 mm
RT21071100
RT21071110
Specification (mm)
0.007
0.04
07
89
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