11 24 571 Replacing all connecting rod bearing shells (N55)

Special tools required:

IMPORTANT: Modified procedure:
All crank pins are connected with the crankshaft.
The Blue/Red connecting rod bearing shell colors are no longer fitted in combination.

Necessary preliminary tasks:

Removing OIL SUMP .

IMPORTANT: All crankshaft crank pins are classified.
The identification (2) is located on the first crank web.

Optional classifications (2) per connecting rod

On the connecting rod and connecting rod bearing cap:

r. Connecting rod = Yellow.

Connecting rod bearing cap = Red.

b. Connecting rod = Violet.

Connecting rod bearing cap = Blue

Fig 1: Identifying Identification On First Crank Web

G09836172

Courtesy of BMW OF NORTH AMERICA, INC.

Example:

Possible classification: b r r r r r

Cylinder Classification b 1:

Violet (connecting rod)/\Blue (connecting rod bearing cap)

Cylinder Classification r 2:

Yellow (connecting rod)/Red (connecting rod bearing cap)

Cylinder Classification r 3:

Yellow (connecting rod)/Red (connecting rod bearing cap)

Cylinder Classification r 4:

Yellow (connecting rod)/Red (connecting rod bearing cap)

Cylinder Classification r 5:

Yellow (connecting rod)/Red (connecting rod bearing cap)

Cylinder Classification r 6:

Yellow (connecting rod)/Red (connecting rod bearing cap)

Release connecting rod bolts (1).

Remove connecting rod bearing cap (2).

Fig 2: Identifying Connecting Rod Bearing Cap And Bolts

G09836173

Courtesy of BMW OF NORTH AMERICA, INC.

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

Gently release connecting rod from crankshaft.

Remove connecting rod bearing shells (1 and 2).

Use new connecting rod bearing shells according to code letter.

Installation note:

Pay attention to guide lugs during installation.

Fig 3: Identifying Connecting Rod Bearing Shells

G09836174

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: All crankshaft crank pins are classified.

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

Check connecting-rod bearing play.

Piston in BDC position.

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

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

Fit connecting rod bearing cap so that pairing letters match up.

Fig 4: Fitting Special Tool 00 2 590 (Plastigage Type PG 1) To Oil-Free Crankshaft

G09836175

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: Do not distort connecting rods or crankshaft.

Use the old connecting rod bolts to check connecting-rod bearing play.

Tighten down connecting rod bolts with special tool 00 9 120 .

Tightening torque 11 24 1AZ .

Fig 5: Tightening Down Connecting Rod Bolts Using Special Tool 00 9 120

G09836176

Courtesy of BMW OF NORTH AMERICA, INC.

Unscrew connecting rod bearing cap. Read off connecting rod bearing play at width of flattened Plastigage on measurement scale.

CONNECTING ROD BEARING PLAY .

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

Fig 6: Locating Marks On Connecting Rod Bearing Play
Courtesy of BMW OF NORTH AMERICA, INC.

Tightening torque 11 24 1AZ .

Assemble engine.