Chery S11 / Chery QQ. Manual — part 118

Chery QQ Service Manual

Mechanical Part of SQR 472Engine

41

2.2.5

If it is beyond the limit, replace the bearing

bushing.

Notice: Replacing the bearing bushing with the product

of the same manufacturer’s brand. The thickness of the

connecting rod bushing which meets the requirements of

clearance = diameter of big end hold – axial diameter of

connecting rod – standard value of bearing bushing

clearance

2.2.6

Remove the connecting rod bearing cap and the

connecting rod bearing bushing

2.2.7

Put vinyl-resin protecting jacket on the threaded

part of the connecting rod bolt so as to prevent the bolts

from scraping the cylinder hole and the crannkshaft

connecting rod journal, and then disassemble the piston

connecting rod by using the hammer handle striking it out.

2.3 Inspect the axial clearance of crankshaft

2.3.1

Measure the axial clearance of the crankshaft with

a dial gauge, if it is beyond the limit, it is necessary to

replace the axial thrust plate or the crankshaft.

Standard value: 0.089-0.211mm

Limit: 0.30mm

Item

Standard value

1.9

-0.11

-0.03

Connecting Rod

Connecting Cover

Protection Sleeve

Chery QQ Service Manual

Mechanical Part of SQR 472Engine

42

2.4 Inspect the crankshaft for its radial clearance.

2.4.1 Remove the crankshaft bearing cap by softly

tapping with a resin hammer.

2.4.2 Clean the inside and surface of the bearing bushing,

the inside and surface of the bearing cap, the cylinder wall

and journal. Inspect them for abrasion and damage

carefully.

2.4.3 Adjust the radial clearance of the crankshaft with a

clearance gauge, and tighten the bearing bushing cover

bolts with the specified torque.

Torque: 70±3.5N.m

Notice: After tightening the bolts, the rotating torque of

the crankshaft should be less than 1Nm
（The torque of crankshaft without piston connecting rod）

2.4.4 Remove the bearing cap and measure the maximum

width with a clearance gauge. If the measurement result

exceeds the limit, replace the bearing bushing.

Standard value: 0.025-0.069mm

Limit:

0.10mm

2.4.5 Remove the main bearing bushing cap of the

crankshaft, crankshaft, crankshaft bearing bushing and

crankshaft axial thrust plate

Notice: Tighten the bolts for the crankshaft bearing cap

in the order shown in the right figure. Tighten the bolts for

three times, then the torque must be up to the specified

value.

Protection Sleeve

Clearance Gauge

Width Compare of Clearance Gauge

Chery QQ Service Manual

Mechanical Part of SQR 472Engine

43

2.5 Disassembly and assembly of the piston and

connecting rod assembly

2.5.1

Remove the first ring, second ring and the oil

ring with a pair of piston ring moving pliers.

Notice: Don’t get the piston and piston ring of each

cylinder confused.

2.5.2

Remove the piston, connecting rod and the

piston pin with special tool.

Disassemble the piston pin with special tool as indicated in

the right figure.

① As indicated in the right figure, disassemble the piston

which is at the state mentioned above with special

tools. Remove the piston pin with special tool, and

then remove the piston and the connecting rod.

3 Cleanup

3.1 Cylinder Body

Warning:

In the course of cleanup, protect your eyes

with eyeglass.

3.1.1

Clean up the cylinder body, cylinder head, oil

pan, oil pump and the oil seal with a flat blade.

3.2 Piston

Warning:

In the course of cleanup, protect your eyes

with eyeglass.

3.2.1

Use an old ring to remove the carbon in ring

groove.

3.2.2

Remove the carbon of parts with scavenger.

Notice: Don’t use hard articles such as metal brush.

Special Tool

Special Tool

Chery QQ Service Manual

Mechanical Part of SQR 472Engine

44

4 Routine Inspection

4.1 Cylinder Body

4.1.1 Inspect the top surface of cylinder body for its

flatness

(1) Measure at the six points shown in the right figure

with a ruler and a feeler gauge.

Limit:

0.08mm

4.1.2 Use of bore gauge

Measure the cylinder bore at the positions as indicated in

the right figure with a bore gauge, and figure out the

difference between the maximum value and the miximum

value. If the difference exceeds the limit, repair or replace

the cylinder.

Limit:

0.03mm

[Reference] Roundness: A-B or a-b

Cylindric degree: A-a or

[Reference] Standard

diameter

of

cylinder:

φ72.00-72.01mm

4.2 Piston

4.2.1

Inspect the piston pin hole for its clearance

Measure the piston pin at several positions with a

micrometer caliper shown in the figure, make the

maximum value as the diameter of pin.

4.2.2

Measure the diameter of piston pin at several

positions with an inner-diameter dial gauge as shown in the

figure, make the minimum value as the diameter of the pin

hole.

Work out the clearance with the difference between the

pin diameter and pin hole diameter, if the difference is

beyond the standard value, replace the piston pin or piston.

Standard value: 0.004-0.009mm

Limit: 0.015mm

Upper Stopper Position of Piston

Lower Stopper Position of Piston

Measurement

Position

of

Piston Pin