Remove/install piston

AR03.10-T-7021BB

Remove/install piston

10.11.11



Removing

1

Open liftgate

2.1

Open left rear maintenance flap

Model 671.015/020/021/030/042/332/333

3

Raise vehicle

Model 613.358/388

AR00.60-T-1000B

Model 671.015/020/021/030/042/332/333

AR00.60-T-1000AA

4

Remove lower engine compartment paneling

Model 613.358/388

AR61.20-T-1105B

Model 671.015/020/021/030/042/332/333

AR61.20-T-1105AA

5

Drain engine oil or extract



Engine oil and filter change

AP18.00-T-0101BB

6

Remove oil pan

Model 613.358/388

AR01.45-T-7500BA

Model 671.015/020/021/030/042/332/333

AR01.45-T-7500AA

7

Remove cylinder heads

AR01.30-T-5800BB

8

Remove oil pump

Model 613.358/388

AR18.10-T-6020BA

Model 671.015/020/021/030/042/332/333

AR18.10-T-6020AA

9

Remove combustion residues on cylinder barrel

 Carefully remove combustion residues above the top land zone using a scraper in order not to damage the cylinder barrel.

10

Remove connecting rod bearing cap (5)

 Turn crankshaft until connecting rod journal is at the bottom. Remove connecting rod bolts (6).

Before removing check whether there is a marking (arrow) on the connecting rod bearing cap (5) and associated connecting rod (4).

Identify if necessary.

11

Remove piston (1) together with connecting rod (4) from the crankcase

 Turn crankshaft until connecting rod journal is at the top. Push connecting rod (4) with piston (1) out of cylinder liner.

 Use a plastic or wooden wedge for pressing out the connecting rod (4). Ensure that the connecting rod bearing shell (7) remaining in the connecting rod (4) is not damaged. Mark installation position of connecting rod bearing shell (7).

12

Clamp connecting rod (4) in a vice

 Use soft protective jaws.

13

Mark piston pin (2), piston (1) and connecting rod (4) relative to each other

 Marking of the installation position and how the parts fit together for reinstallation.

14

Remove a retaining ring (3) from the piston boss

15

Press out piston pin (2) in direction of the removed circlip (3) and take piston (1) off the connecting rod (4)

 When assembling, pay attention to marking of installation position of piston relative to piston pin and piston relative to connecting rod.

16

Remove second retaining ring (3) from piston boss

17

Remove piston rings

AR03.10-T-7311BB



Checking

 First of all clean all parts to be inspected. Free up radial grooves and oil return bores on pistons of combustion residues.

18

Check piston crown, piston skirt for damage and wear

 Replace piston if necessary. Piston must be replaced only together with the matching cylinder liner as a replacement part repair kit: 

Remove/install/seal cylinder liner

AR01.40-T-9324BB



Notes for assessing piston wear from dust/particulate damage

AH03.10-N-0001-01A

19

Check cylinder liners for damage and wear

 Replace cylinder liner if necessary. Replace cylinder liner only together with the matching piston as a replacement part repair kit: 

Remove/install/seal cylinder liner

AR01.40-T-9324BB

Cylinder liner inner 

*BE01.40-N-1001-03G

Quick calipers for internal measurements

Outside micrometer



Notes for assessing wear to cylinder wall in the case of dust damage

AH01.40-N-0001-01A

20

Inspect piston rings

 Check for cracks and chippings in the coating. Perform inspection after removing and reinstalling piston rings, install new piston rings if necessary.

21

Inspect connecting rod and connecting rod bearings

AR03.10-T-6111BB



Measure

22

Measure piston ring end gap

 If the measurement obtained does not comply with the specification, a new piston ring should always be installed.

AR03.10-T-7311-02A

*BE03.10-N-1001-05H

Feeler gauge

23

Measure shank length (L) of connecting rod bolts

 Replace connecting rod bolt, if necessary.

*BE03.10-N-1002-01J

Vernier caliper

Tool kit

gotis://G_58.3_05.0

24

Measure piston pin bore and piston pins

 Inner diameter of piston pin bore and outer diameter of piston pin.

*BE03.10-N-1003-02I

*BE03.10-N-1004-02I

Quick calipers for internal measurements

Outside micrometer



Install

25

Install piston rings

AR03.10-T-7311BB

26

Measure vertical clearance of piston rings

 If the side clearance of the piston rings is too large, replace pistons and piston rings together.

AR03.10-T-7311-01A

Side clearance for piston rings

*BE03.10-N-1002-05H

Feeler gauge

27

Install one retaining ring (3) into piston boss

28

Clamp connecting rod (4) in a vise

 Use soft protective jaws.

29

Fit piston (1) onto connecting rod (4) and install piston pin (2)

 Oil piston pin and insert into the piston and connecting rod by hand.

30

Install the second retaining ring (3) into the piston boss

31

Check ease of movement of piston pin (2)

 By moving piston back and forth.

32

Insert connecting rod bearing shell (7) to connecting rod (4)

 Lubricate contact surface slightly. If connecting rod bearing shells are re-used, pay attention to installation marking. The lug of the connecting rod bearing shell must be located in the slot of the connecting rod.

33

Clean cylinder liner and piston contact surface using a clean cloth

 Lightly lubricate using engine oil.

34

Insert piston (1) with connecting rod (4) into the cylinder liner

 Displace piston ring end gaps in the process evenly relative to each other.

The arrow in the piston crown must point in the direction of the vibration damper.

35

Guide piston ring tensioning strap loosely over piston rings and tighten to outer diameter of the piston (1)



*000589383100

36

Press piston (1) into cylinder liner

 Use handle of a hammer to press it in sufficiently until connecting rod bearing is touching connecting rod bearing journal of the crankshaft.

37

Insert connecting rod bearing shell (7) into connecting rod bearing cap (5)

 Lubricate contact surface slightly. If connecting rod bearing shells are re-used, pay attention to installation marking. The lug of the connecting rod bearing shell must be located in the slot of the connecting rod bearing cap.

38

Install connecting rod bearing cap (5)

 Pay attention to marking on connecting rod bearing cap.



*BA03.10-N-1001-01H

39

Measure piston projection

AR03.10-T-7041-01A

*BE03.10-N-1005-02I



*001589532100



*343589004000

40

Install oil pump

Model 613.358/388

AR18.10-T-6020BA

Model 671.015/020/021/030/042/332/333

AR18.10-T-6020AA

41

Install cylinder heads

AR01.30-T-5800BB

42

Install oil pan

Model 613.358/388

AR01.45-T-7500BA

Model 671.015/020/021/030/042/332/333

AR01.45-T-7500AA

43

Pour in engine oil



Engine oil and filter change

AP18.00-T-0101BB

44

Install lower engine compartment paneling

Model 613.358/388

AR61.20-T-1105B

Model 671.015/020/021/030/042/332/333

AR61.20-T-1105AA

45

Lower vehicle

Model 613.358/388

AR00.60-T-1000B

Model 671.015/020/021/030/042/332/333

AR00.60-T-1000AA

46.1

Close left rear maintenance flap

Model 671.015/020/021/030/042/332/333

47

Close liftgate

Number

Designation

Engine
457.941/942

Engine
457.944

BE01.40-N-1001-03G

Cylinder liner inner diameter

Code letter A

mm

127.990 to 127.995

127.990 to 127.995

Code letter B

mm

127.995 to 128.005

127.995 to 128.005

Code letter C

mm

128.005 to 128.010

128.005 to 128.010

Number

Designation

Engine
457.941/942

Engine
457.944

BE03.10-N-1001-05H

Piston ring end clearance

Groove I

New

mm

0.60 to 0.75

0.60 to 0.75

Keystone ring

Wear limit

mm

1.0

1.0

Groove II

New

mm

0.60 to 0.75

0.60 to 0.75

Taper-faced ring with internal angle

Wear limit

mm

1.0

1.0

Groove III

New

mm

0.40 to 0.55

0.40 to 0.55

Bevel-edge ring with garter spring

Wear limit

mm

1.0

1.0

BE03.10-N-1002-05H

Piston ring vertical clearance

Taper-faced ring

mm

0.07 to 0.105

0.07 to 0.105

Bevel-edge ring with garter spring

mm

0.03 to 0.065

0.03 to 0.065

Keystone ring

mm

0.047 to 0.102

0.047 to 0.102

Number

Designation

Engine
457.941/942

Engine
457.944

BE03.10-N-1003-02I

Piston pin bore

mm

52.004 to 52.012

52.004 to 52.012

BE03.10-N-1004-02I

Piston pin dia.

mm

51.995 to 51.998

51.995 to 51.998

BE03.10-N-1005-02I

Piston projection at TDC relative to cylinder crankcase contact surface

mm

0.224 to 0.715

0.224 to 0.715

Number

Designation

Engine
457.941/942/944/945/946

BE03.10-N-1002-01J

Connecting rod bolt

Thread diameter

M

161.5

Shank length (L) when new

mm

67.0 to 67.5

permissible shank length (L)

mm

68.5

Number

Designation

Engine 457.941/
942

Engine 457.944

BA03.10-N-1001-01H

Screw/bolt, connecting rod bearing cap to connecting rod

Stage 1

Nm

100

100

Stage 2

°

90

90