Mazda 6. Manual - part 5

ENGINE 

B–9

B

.

•

Three kinds of main bearings are available depending on the oil clearance.

(mm {in})

End Of Sie

BALANCER UNIT

A6E222411301T02

Outline

•

The cassette type balancer, which is separated 
from the engine, has been adopted for the L3 
engine models to reduce vibration from the 
engine.

.

AME2224N007

1

Upper main bearing

2

Lower main bearing

3

Thrust bearing

4

Supplying engine oil

5

2 holes Supplying engine oil

6

Main bearing cap

7

Main bearing

Bearing 

size

Color

Bearing thickness

Standard

Green

2.506—2.509 {0.0987—0.0988}

0.25 {0.01} 

Oversize

2.628—2.634 {0.1035—0.1037}

0.50 {0.02} 

Oversize

2.753—2.759 {0.1084—0.1086}

1

Cassette type balancer unit

2

balance shaft

AME2224N401

B–10

ENGINE 

Structure

•

The balancer unit is configured with two balancer shafts (No.1 and No.2) with weights, the balancer unit case 
and the adjust shim which adjusts the amount of backlash in the crankshaft.

•

The two balancer shafts (No.1 and No.2) are driven by the drive gear which is attached to the crankshaft.

•

The balancer unit cannot be disassembled because it is a precision unit.

Operation

•

The rotary motion is transmitted from the drive gear, which is between the back of the No.3 cylinder and the 
No.4 main journal, directly to the No.1 balance shaft with driven gear. Then the balance unit transmits the 
rotation motion to the No.2 balance shaft. The ratio of gears, which are attached to No.1 and No. 2 balancer 
shafts, has been set so that the gear rotates at twice the velocity of the crankshaft. The balancer shaft's rotation 
velocity counterbalances (generate the force in the opposite direction) the rotation inertial force (secondary 
inertial rotation force) from the crankshaft.

.

•

Replace the adjust shim to adjust backlash. There are 40 kinds of adjuster shim depending on the thickness. 
To determine the kind, check the engraved identification mark (2 digits) on the adjust shim.

AME2224N402

1

Adjust  shim 

2

Crankshaft

3

Engine front 

4

Balancer unit case

5

Weights

6

No.2 balance shaft

7

Drive gear

8

No.1 balance shaft with driven gear

ENGINE 

B–11

B

.

End Of Sie

CRANKSHAFT PULLEY

A6E222411371T01

Structure

•

The crankshaft position (CKP) signal detecting blade has been adopted for the crankshaft pulley. And the 
torsional damper, which prevents the crankshaft from wobbling, has also been adopted for the crankshaft.

•

The positioning key slot, which is used for attaching the pulley to the crankshaft, has been decommissioned. 
For aligning the crankshaft pulley to the crankshaft, use the positioning hole on the engine front cover and the 
crankshaft pulley. 

•

Crankshaft pulley rock bolt is the plastic region tightening bolt, which can be tightened in 2 motions. It insures a 
stable axis during tightening.

.

End Of Sie

AME2224N403

1

Cylinder block

2

Engraved identification mark (2 digits)

1

Elevation view

2

Sectional view

3

Braid for CKP sensor signal detection

4

Hole for pulley positioning

5

Torsional damper

AME2224N012

B–12

ENGINE 

ENGINE FRONT COVER

A6E222401001T01

Structure

•

The engine front cover is made of aluminum alloy, and is integrated with the No.3 engine-mounting bracket, to 
improve noise absorption and decrease weight.

•

The hole for crankshaft pulley positioning bolt, the service hole for unlocking the chain adjuster ratchet, and the 
service hole for securing the tensioner arm when loosening the timing chain, are on the engine front cover.

•

The oil line and the integrated oil filter are on the L3 engine front cover.

.

End Of Sie

AME2224N011

1

Elevational view

2

Service hole for tensioner arm fixation

3

Service hole for chain tensioner lock release

4

No.3 engine mount bracket

5

Bolt hole crankshaft pulley positioning

6

Back view

7

Oil filter

8

Oil passage to OCV