11 24 571 Replacing All Connecting Rod Bearings (N51)

Special tools required: 

For the following special tools, refer to MAINTENANCE AND GENERAL INFORMATION - SPECIAL TOOLS -- 128I .

• 00 2 590 
• 00 9 120 

Necessary preliminary tasks: 

• Removing oil pan  . See 11 13 000 REMOVING AND INSTALLING, SEALING OR REPLACING OIL SUMP (N51) .

Possible classifications per connecting rod at top and bottom:

r: Red

b: Blue

Only one  color may be fitted per big end and connecting rod.

In direction of arrow from (1 to 2) crank pin (1 to 6).

Fig 1: Locating Crankshaft Crank Pins

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Example: 

Possible classification:

Cylinder Classification Red / Red.

1:

Cylinder Classification Blue / Blue.

2:

Cylinder Classification Blue / Blue.

3:

Cylinder Classification Red / Red.

4:

Cylinder Classification Red / Red.

5:

Cylinder Classification Blue / Blue.

6:

Release conrod bolts (1).

Remove connecting rod bearing cap (2).

Fig 2: Identifying Conrod Bolts And Connecting Rod Bearing Cap

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Gently release connecting rod from crankshaft.

Remove bearing shells (1 and 2).

Install new conrod bearing shells.

Fig 3: Removing Bearing Shells

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Installation: 

Pay attention to guide lugs during installation.

In each case insert only one color of bearing shell (1 and 2) for each conrod.

Check conrod bearing clearance.

Piston in BDC position.

Determine bearing clearance, ensure that bearing points are free from oil and grease.

Fit special tool 00 2 590 (Plastigage Type PG 1) to oil-free crankshaft.

Fit bearing cap so that pairing letters match up.

Fig 4: Locating Bearing Points

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Use the old conrod bolts to check conrod clearance.

Tighten down conrod bolts with special tool 00 9 120. See Fig 5.

Tightening torque. See 11 24 1AZ in 11 24 CONNECTING RODS AND BEARINGS .

Fig 5: Identifying Special Tool (00 9 120)

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Remove bearing cap. Read off bearing clearance at width of crushed plastic thread (Plastigage) with aid of measuring scale.

Conrod bearing clearance  .

• Remove Plastigage
• Coat crankshaft and bearing shells with oil.
• Install new conrod bolts and tighten down with special tool 00 9 120.

Tightening torque. See 11 24 1AZ in 11 24 CONNECTING RODS AND BEARINGS .

Fig 6: Inspecting Bearing Clearance Using Plastigage

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Assemble engine.