11 24 571 Replacing all connecting rod bearing shells (N52T)

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 work:

Remove OIL SUMP

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

Possible classifications per connecting rod and connecting rod bearing cap:

r: Connecting rod/bearing cap = Red.

b: Connecting rod/bearing cap = Blue.

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

Classification (2) on crank web for crank pins (1 to 6).

Example:

Possible classification: b r r r r r

Zyl 1: Classification b = blue/blue.

Zyl 2: Classification r = red/red.

Zyl 3: Classification r = red/red.

Zyl 4: Classification r = red/red.

Zyl 5: Classification r = red/red.

Zyl 6: Classification r = red/red.

Fig 1: Identifying Main Bearing Classification ID Codes

Courtesy of BMW OF NORTH AMERICA, INC.

Release connecting rod bolts (1).

Remove connecting rod bearing cap (2).

Fig 2: Identifying Connecting Rod Bearing Cap And Bolts

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).

Install new connecting rod bearing shells.

Installation note:

Pay attention to guide lugs during installation.

IMPORTANT: All crankshaft crank pins are classified.

Fig 3: Identifying Connecting Rod Bearing Shells

Courtesy of BMW OF NORTH AMERICA, INC.

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: Identifying Connecting Rod Bearing Cap Pairing Letters

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: Identifying Special Tool (00 9 120)

Courtesy of BMW OF NORTH AMERICA, INC.

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

Connecting-rod bearing play . See CONNECTING RODS AND BEARINGS (N52T) .

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 .

Tightening torque: 11 24 1AZ .

Fig 6: Checking Connecting-Rod Bearing Play

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.