11 24 571 Replacing all connecting rod bearing shells (N52K)

WARNING: This page is about a different variant/trim than selected.

Special tools required:

IMPORTANT: All crank pins are connected with the crankshaft.
Modified procedure: The colors of the connecting rod bearing shells are the same at the top and bottom.
The Blue / Red connecting rod bearing shell colors are no longer fitted in combination.

Necessary preliminary tasks:

Remove oil sump

IMPORTANT: All crankshaft crank pins are classified.

Possible classifications per connecting rod at top and bottom:

r: Red

b: Blue

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

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

Example:

Possible classification: rbbrrb

Fig 1: Connecting Rod Classifications

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Cylinder Classification Red / Red

Cylinder Classification Blue / Blue
Cylinder Classification Blue / Blue
Cylinder Classification Red / Red
Cylinder Classification Red / Red
Cylinder Classification Blue / Blue

Release conrod bolts (1).

Remove connecting rod bearing cap (2).

Fig 2: Conrod Bolts And Connecting Rod Bearing Cap

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IMPORTANT: Risk of damage to cylinder wall and to crankshaft.

Gently release connecting rod from crankshaft.

Remove connecting rod bearing shells (1 and 2).

Install new conrod bearing shells.

Installation:

Pay attention to guide lugs during installation.

IMPORTANT: All crankshaft crank pins are classified.

Fig 3: Connecting Rod Bearing Shells

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

Check conrod bearing clearance.

Piston in BDC position.

To determine the connecting rod bearing play, make sure that the bearing points are clean and free from oil and grease.

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

Fit conrod bearing cap so that pairing letters match up.

Fig 4: Locating Conrod Bearing Clearance

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IMPORTANT: Do not distort conrods or crankshaft.

Use the old conrod bolts to check conrod clearance.

Tighten down conrod bolts with special tool 00 9 120 .

Tightening torque: 11 24 1AZ, see 11 24 CONNECTING RODS AND BEARINGS .

Fig 5: Special Tool (00 9 120)

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Unscrew conrod bearing cover. Read off conrod bearing play at width of flattened plastic thread on measurement scale.

Conrod bearing clearance, see 11 24 CONNECTING RODS AND BEARINGS N52K B25 .

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

Tightening torque: 11 24 1AZ, see 11 24 CONNECTING RODS AND BEARINGS .

Fig 6: Reading Conrod Bearing Play At Width Of Flattened Plastic Thread On Measurement Scale

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.