11 24 571 Replacing all connecting rod bearings (N47)

Special tools required: 

• 00 2 590
• 00 9 120
• 11 2 110

Necessary preliminary tasks: 

• Removing all PISTONS 

Insert one blue and one red bearing shell for each connecting rod (irrespective of the color coding on the connecting rod shaft).

Fig 1: Connecting Rod Mark And Bearing Shell

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Install piston.

Check connecting-rod bearing play.

Piston in BDC position.

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

Fit bearing caps so that matching numbers match up.

Fig 2: Bearing Caps Numbers

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

00 9 120 Tighten down connecting rod bolts with special tool or special tool. 11 2 110 Tightening torque: 11 24 1AZ .

Fig 3: Tightening Connecting Rod Bolts Using Special Tool (00 9 120)

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Remove bearing caps.

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

Connecting-rod bearing play  . See ø LARGE CONNECTING ROD EYE (WITHOUT BEARING) and GROUND SIZES OF CONROD BEARING JOURNALS .

Remove Plastigage.

Fig 4: Checking Plastic Thread Bearing Width

Courtesy of BMW OF NORTH AMERICA, INC.

Overview:

Color code/shaft diameter/bearing strength

Rt = red

Bl = blue

1. Crankshaft journal
2. Bearing clearance
3. Bearing shells: red or blue
4. Connecting rods
   Fig 5: Bearing Clearance

   Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.