Servicing, aligning and mounting conrod bearings - RA03001043130X(03-3130)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

Preceding work:

Conrod removed

Operation no. of operation texts and work units or standard texts and flat rates:

03-6111 - 03-6401

Fig 1: Measuring Conrod Bearing Basic Bore

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

REPAIRING

Conrod bolts	check (03-3100) .
Conrod bearing caps	install; oil thread and bolt head contact surface for this step and tighten to 40 Nm.
Conrod bearing basic bore	measure (Fig. A). NOTE: If basic bore exceeds the value of 51.619 mm or is conical, dress contact surface of conrod bearing cap to max. 0.02 mm. Machine conrod cap together with conrod.
New conrod bush	press in (Fig. B). NOTE: Press in new conrod bush so that the oil drillings are aligned (arrows). Insertion pressure 2450 N.
Conrod bush	turn or ream.
Contact surfaces of conrod at side	dress on a dressing plate.

Fig 2: Identifying Conrod Bearing Bore To Conrod Bush Bore Alignment

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

ALIGNING

Conrod	check with bearing shells and piston pins installed with conrod inspection equipment.
Conrod	align with conrod aligning equipment.
Parallelism of conrod bearing bore to conrod bush bore	align (Fig. C).
Twist of conrod bearing bore to conrod bush bore	align (Fig. D).

Fig 3: Measuring Conrod Bearing Bore To Conrod Bush Bore

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

FITTING NEW BEARINGS

Conrod basic bore	measure, note.
Conrod bearing journal Ø	measure, note.
Conrod radial bearing play	calculate.
Conrod bearing shell	match.
Conrod	install on pistons (03-3160) .

Fig 4: Identifying Conrod Basic Bore And Conrod Bearing Shell Dimension

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

DATA

Engine	104.94	104.98/99
Center of conrod bearing bore to center of conrod bush bore (L)	148.995 - 149.005	144.995 - 145.005
Width of conrod at conrod bearing bore (B)	21.948 - 22.000
Width of conrod at conrod bush bore (b)	21.948 - 22.000
Conrod bearing shell basic bore (D1)	51.600 - 51.619
Conrod bush basic bore (d1)	24.500 - 24.571

DATA

Conrod bush inner Ø (d)	22.007 - 22.013
Piston pin play in conrod bush	0.013 - 0.018
Peak-to-valley height of conrod bush on inside	0.005
Permissible twist of conrod bearing bore to conrod bush bore	0.15
Permissible difference in axial parallelism of conrod bearing bore to conrod bush bore	0.07
Permissible difference in concentricity of conrod bearing bore	0.01
Permissible difference in weight of complete conrod within an engine	4 g

CRANKSHAFT IDENTIFICATION AND MACHINING DIMENSIONS

Crankshaft

Size

Color coding on crankshaft web ⁽²⁾

Machining dimensions ⁽¹⁾

Conrod bearing journal Ø

Standard

none

47.955 - 47.965

Standard 1 ⁽²⁾

orange

47.945 - 47.955

Standard 2 ⁽²⁾

blue

47.935 - 47.945

1st repair size

47.700 - 47.715

2nd repair size

47.450 - 47.465

3rd repair size

47.200 - 47.215

4th repair size

46.950 - 46.965

Conrod bearing journal width

Standard

27.958 - 28.042

Repair size up to

28.300

⁽¹⁾	The crankshaft should be machined so as to maintain the specified bearing play with the existing bearing shells.

⁽²⁾	Up to 12/93

TEST DATA

Conrod bearing play	radial	0.02 - 0.04
Conrod bearing play	axial	piston-guided

CONROD BEARING SHELLS

Color coding

red

yellow

blue

Wall thickness in mm

Standard

1.806 - 1.810

1.810 - 1.814

1.814 - 1.818

Standard 1 ⁽¹⁾

1.811 - 1.815

1.815 - 1.819

1.819 - 1.823

Standard 2 ⁽¹⁾

1.816 - 1.820

1.820 - 1.824

1.824 - 1.828

1st repair size

1.995 - 1.999

2nd repair size

2.060 - 2.064

3rd repair size

2.185 - 2.189

4th repair size

2.310 - 2.314

⁽¹⁾	Standard 1 and standard 2: wall thicknesses are not supplied as replacement parts.

Special tools

Fig 5: Identifying Special Tool (001 589 66 21 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 6: Identifying Special Tool (001 589 53 21 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

COMMERCIALLY AVAILABLE TOOLS

Conrod tester	e.g. Model BC 501 KWT 63128 Dietzenbach
Conrod aligning tool	e.g. Model BC 503 KWT 63128 Dietzenbach
Quick-caliper for internal measurements Ø 20 -40 mm Ø 40 -60 mm
Micrometer 0 - 25 mm 50 - 75 mm

NOTE: Conrod and conrod caps are marked together (arrow).

Conrods which have been overheated because of bearing damage (blue discoloration) must not be re-used.

The conrod shaft must not have any cross scores and notches.

Conrods with machined conrod bush are supplied as a replacement part.

The conrod and the conrod cap are located relative to each other with fit sleeves.

Pay attention to difference in weight when replacing the conrod.

Fig 7: Locating Conrod And Conrod Caps Marked

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.