Chery A15. Manual — part 13

CRANKSHAFT

CRANKSHAFT, CRANKSHAFT THRUST
SPACER, BEARING SHELL AND MAIN
BEARING CAP

Removal

Check the axial clearance of the crank shaft before
removal.

Kiss the end side of the crank shaft with the
contacts of a dial gauge (less degree of shrinkage).
Push the crank shaft away from the contacts and
adjust the dial gauge to 0, then push the crank shaft
to the direction of contacts as possible with a0 stout
carrying pole. Check the reading of the dial gauge,
which shall be the axial clearance. The axial
clearance of a crank shaft is 0.092-0.303mm.

The leaf of a clearance gauge can be used to check
the axial clearance of a crank shaft if there is no
dial gauge, which shall be placed between the third
main bearing cap and crank shaft (push and pull the
crank shaft).

Loosen the bolts and studs of the main bearing
shell, (beginning from the middle bearing cap),
take out the bolts and the threaded rods to remove
the main bearing cap and the lower shell of the
main bearing shell. This lower shell shall still
remain in the main bearing cap.

Take the crank shaft out.

Remove the crank shaft thrust spaces (2 pieces)
from the cylinder block.

Inspection

Check the main journal and main bearing shell
clearance.

Clean the main journal of the crank shaft, the
internal bore of the main bearing cap and main
bearing shell with a non-woven fabrics. Place the
plastic clearance gauge (its length slightly shorter
than the length of the main journal) on the main
journal, which shall be in parallel with the
generator of the main journal.

Note: Do not rotate the crank shaft！

B-28

Install the main bearing cap. Tighten the bolts of
the main bearing cap at the moment of 90-100N.m
by hands. Do not rotate the crank shaft.

Remove the main bearing bolts. Carefully take
out the main bearing cap and arrange them in order.
Read the bearing clearance according to the ratio
on the envelope of the plastic clearance gauge.
Check the bearing clearance from the third main
bearing and extend to both sides. The main bearing
clearance shall be 0.011—0.058mm.

Check the bearing clearance of the connecting rod.

Check the bearing clearance of the connecting rod
according to the above methods. The bearing
clearance of the connecting rod shall be 0.006—
0.06mm.

Size of connecting rod journal and connecting-rod bearing shell

Class

Diameter of

connecting rod

journal

(unit: mm)

Thickness of

connecting-rod

bearing shell

(unit: mm)

Standard 47.89—47.91 1.480—1.487

Downsized

by 0.025

47.89—47.91 1.492—1.499

Downsized

by 0.25

47.64—47.66 1.605—1.612

Downsized

by 0.5

47.39—47.41 1.730—1.737

Downsized

by 0.75

47.14—47.16 1.855—1.862

Downsized

by1.0

47.89—46.91 1.980—1.987

B-29

Diameter of main journal and size of main bearing shell

Class

Diameter of main

journal (unit: mm)

Diameter of the main bearing

bore of the cylinder block

(unit: mm)

Thickness of the main

bearing shell

(unit: mm)

Standard 57.98—58.00 62.2935+0.0065 2.131—2.138

Oversized by 0.4

57.98—58.00

62.6935+0.0065 2.331—2.338

Downsized by 0.02

57.98—58.00

62.2935+0.0065 2.141—2.148

Downsized by 0.25

57.73—57.75

62.2935+0.0065 2.256—2.263

Downsized by 0.50

57.48—57.50

62.2935+0.0065 2.381—2.388

Downsized by 0.75

57.23—57.25

62.2935+0.0065 2.506—2.513

Downsized by 0.25

and oversized by

0.4

57.73—57.75 62.6935+0.0065 2.456—2.463

Downsized by 0.50

and oversized by

0.4

57.48—57.50 62.6935+0.0065 2.518—2.558

Downsized by 0.75

and oversized by

0.4

57.23—57.25 62.6935+0.0065 2.706—2.713

Size of crank shaft thrust, thrust spacer and cylinder block thrust

Class

Size of cylinder block thrust

(unit: mm)

Size of crank shaft thrust

(unit: mm)

Thickness of thrust

spacer (unit: mm)

Standard 24+0.03 28.825-28.875

2.326+0.025

Oversized

by 0.38

24+0.03 29.205-29.255

2.516+0.025

2 thrust spacers

B-30

Installation

Before installation, tap the threaded hole on
the cylinder block with tapping drill,
especially those of the cylinder head bolts and
main bearing bolts.

Cylinder head bolt: M10X1.5~6H

Main bearing bolt: M12X1.75~6H

Installation of the whiney key of the crank
shaft: gently drive the whiney key into the key
slot. The clearance between the whiney key
and key slot is 0.00~0.051mm. Check the
protrusion after the whiney key is installed,
which shall be 1.392~1.739mm.

There are two pieces of crank shaft thrust
spacers, which are installed on the front and
rear thrust surfaces. Before installation, apply
some motor oil on the side of the thrust spacer
with oil groove and make this side towards the
cylinder block and the other side towards the
crank shaft.

Apply some motor oil on the main journal,
connecting rod journal, thrust surface and
bearing shell before the crank shaft is
installed.

The top of the main bearing cap is cast with
numbers- 1, 2, 3, 4, 5 and one arrow. During
the assembly, start the installation in a
front-to-back order and enable the guide
finger towards the front end surface of the
cylinder block. The width of 1, 2, 4, 5 main
bearing cap is same, but that of the third main
bearing cap is larger than others. The location
of the main bearing cap depends on the rabbet
and the rabbet and the cylinder block is
interference fit, with the interference to be
0.025~0.145mm. After the assembly, the sides
of the first and fifth main bearing cap shall be
even with or lower than the back and front
end surface of the cylinder block.

Among the main bearing bolts, 9 are
hexagonal-head flanged bolts and 1 is stud.
For transverse engine, the stud shall be
installed on the left threaded hole of the
second main bearing cap (seeing from the
front) for installing the support of the suction
strainer. For a north-south engine, the stud

B-31