Chery Tiggo 5 (T21). Manual — part 125

07–

86

07

40.Remove the crankshaft main bearing shell.

a. Slightly push the crankshaft main bearing upper shell

(1) in the direction of arrow and remove it carefully.

HINT:

 Remove other crankshaft main bearing upper

shells from the cylinder block in the same way.

 Remove the crankshaft main bearing lower shells

from the crankshaft frame in the same way.

 Pay attention to the notch position. Push out the

bearing shell carefully as shown in the illustration.
It is difficult to push out the bearing shell and the
parts may be damaged if pushing in the opposite
direction.

Inspection

1. Check cylinder block.

Clean engine block thoroughly and check all hole passages for leakage.
Check engine block and cylinder bore for cracks.
Check bottom surface of engine block for cracks.

2. Check flatness of engine block upper surface.

a. Clean the engine block upper surface.
b. Using a precision ruler and feeler gauge, measure the

flatness of engine block upper surface.

It is not allowed to grind the block upper surface. If the
flatness of engine block upper surface exceeds the
limit, replace the engine block.

3. Check cylinder.

a. Cylinder cylindricity and roundness calculation method (for general measurement):

Thrust direction - perpendicular to the axis of crankshaft; Axial direction: Parallel with the axis of
crankshaft
Cylindricity calculation method
Cylindricity is half of the diameter difference measured in the same direction.
Cylindricity in thrust direction = (maximum diameter measured at A, B and C in thrust direction -
minimum diameter measured at A, B and C in thrust direction)/2
Cylindricity in axial direction = (maximum bore diameter measured at A, B and C in axial direction -
minimum bore diameter measured at A, B and C in axial direction)/2
Compare the maximum value measured at the 2 directions with the standard cylinder cylindricity.
Roundness calculation method

1

RT21071020

CAUTION

 DO NOT wash the cylinder at high temperature. Otherwise the cylinder liner will stick out beyond the

engine block.

RT21071030

Measurement Item

Specification

(mm)

Engine Block Upper Surface Flatness

0.04

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Roundness error is half of the diameter difference measured at the same section.
Roundness of Section A = (maximum bore diameter measured in thrust direction and axial direction at
point A - minimum bore diameter measured in thrust direction and axial direction at point A)/2
Roundness of Section B = (maximum bore diameter measured in thrust direction and axial direction at
point B - minimum bore diameter measured in thrust direction and axial direction at point B)/2
Roundness of Section C = (maximum bore diameter measured in thrust direction and axial direction at
point C - minimum bore diameter measured in thrust direction and axial direction at point B)/2
Compare maximum value roundness measured at A, B and C with the standard cylinder roundness.

b. Check cylindricity of cylinder.

Using a cylinder gauge, measure the cylinder bore at
positions A, B and C in the thrust and axial directions.

If the cylindricity or roundness value measured at
positions A, B and C exceeds the specified value,
replace the engine block.

4. Check piston.

a. Using a scraper, remove the carbon deposits on the

top of piston.

b. Using a piston ring, remove the carbon deposits in the

piston ring groove.

Front

12 mm

C

B

A

Center

Axial Direction

Thrust Direction

12 mm

RT21071040

Measurement Item

Specification

(mm)

Cylinder Cylindricity

0.01

Cylinder Roundness

0.008

RT21071050

RT21071060

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c. Using a brush and solvent, thoroughly clean the

piston.

d. Measure the piston diameter with a micrometer at the

position that is approximately 11 mm under the piston
skirt in the vertical direction of piston pin.

If piston diameter is not within the specified range,
replace the piston connecting rod assembly.

5. Check clearance between piston ring and ring groove

side.
Using a feeler gauge, measure the clearance between
new piston ring and ring groove side.

If piston ring side clearance is not within the specified
range, replace the piston connecting rod assembly.

RT21071070

CAUTION

 DO NOT use a wire brush to clean.

11 mm

RT21071080

Measurement Item

Specification

(mm)

Piston Diameter

83.455 ± 0.009

RT21071090

Measurement Item

Specification

(mm)

Piston Ring Side

Clearance

First Ring

0.04 - 0.08

Second Ring

0.025 - 0.070

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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.

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°.

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

45 mm

RT21071100

Measurement Item

Specification

(mm)

Piston Ring End

Gap

First Ring

0.2 - 0.4

Second Ring

0.4 - 0.6

RT21071110

Measurement Item

Specification

(mm)

Crankshaft Main Journal Diameter

54

0
-0.019

Measurement Item

Specification (mm)

Crankshaft Main Journal

Cylindricity

0.007

Roundness

0.04