Repairing and aligning conrod - RA03001203130X(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.

Operation no. of operation texts and work units or standard texts and flat rates 03-6111

Fig 1: Identifying Conrod Length

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

DATA IN MM

Center of conrod bearing bore to center of conrod bush bore (l)	153.95 - 154.05
Width of conrod at conrod bearing bore (B)	21.948 - 22.000
Width of conrod at conrod bush bore (b)	19.90 - 20.10
Basic bore of conrod bearing shells (D1)	51.600 - 51.619
Basic bore of conrod bush (d1)	24.500 - 24.521
Inner dia. of conrod bush (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 deviation of axial parallelism of conrod bearing bore to conrod bush bore	0.07
Permissible deviation of conrod bearing bore from concentricity	0.01
Permissible difference in weight of complete conrod within an engine	4 g

Special tools

Fig 2: Identifying Special Tools (001 589 66 21 00 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 3: Identifying Special Tools (001 589 53 21 00 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

COMMERCIALLY AVAILABLE TOOLS

Conrod tester	e.g.	Model BC 501 KWT W-6057 Dietzenbach
Conrod aligning tool	e.g.	Model BC 503 KWT W-6057 Dietzenbach
Quick calipers for internal measurements Dia. 20 - 40 mm Dia. 40 - 60 mm
Outside micrometer 0 - 25 mm 50 - 75 mm

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

Conrod and conrod cover are marked together. The conrod shaft must not display any cross scores and notches.

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

The conrod and the conrod cover are fixed to each other with dowel sleeve.

Pay attention to difference in weight when replacing conrods.

Repairing

Examine conrod bolts, replace if necessary (03-3100) .
Install conrod cover. Oil thread and bolt head contact surface for this purpose and tighten to 40 Nm.
Measure basic bore of conrod bearings. If the basic bore exceeds 51.619 mm or is conical, dress conrod cover to max. 0.02 mm at its contact surface. Machine conrod cover together with conrod.

Fig 4: Measuring Basic Bore Conrod Bearings
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Press in new conrod bush so that the oil passages are aligned (arrows).
Insertion pressure 2500 N.
Turn or ream conrod bush.
Dress side contact surfaces of conrod on the dressing plate.

Fig 5: Pressing Conrod Bush
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Aligning
Check conrod with bearing shells and piston pins fitted with a conrod tester.
Align conrod with a conrod aligning tool.
Correct parallelism of conrod bearing bore to conrod bush bore.

Fig 6: Identifying Correct Parallelism Of Conrod Bearing Bore To Conrod Bush Bore
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Correct twist of conrod bearing bore to conrod bush bore.

Fig 7: Identifying Correct Twist Of Conrod Bearing Bore To Conrod Bush Bore
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.