11 21 531 Replacing All Main Crankshaft Bearing Shells (N62)

Special Tools Required: 

• 00 2 590
• 00 9 120

Necessary Preliminary Tasks: 

(Engine dismantled)

Clean components before installing.

Preparatory tasks are described in 11 21 500 REPLACING CRANKSHAFT (N62/N62TU) .

Fig 1: Identifying Main Bearing Shell Types

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The letter (1) denotes the crankshaft construction stage.

S= Series.

B= Construction stage 1.

C= Construction stage 2.

The numbers (2) denote the bearing shell classification for the relevant bearing position from 1 to 5 (main bearing cap).

1= yellow.

2= green.

3= violet.

Fig 2: Locating Crankshaft Construction Stage

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The letters (1) denote the bearing shell classification for the relevant bearing position from 1 to 5 in the crankcase and is located on the transmission side in the Vee. The first letter on the left applies to the first bearing position at the front.

Y= yellow.

G= green.

V= violet.

Fig 3: Identifying Bearing Shell Classification

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Fig 4: Identifying Main Bearing Caps With Punch Numbers

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Fig 5: Identifying Main Bearing Cap Number 5

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Unscrew thread support bushings in main bearing caps.

Fig 6: Unscrewing Thread Support Bushings In Main Bearing Caps

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Checking Main Bearing Clearance: 

To check crankshaft bearing clearance, use old main bearing screws.

There must be no oil in the blind holes (risk of cracking).

Do not rotate crankshaft.

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

Fig 7: Checking Crankshaft Bearing Clearance

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1. Tighten all screws on main bearing cover with jointing torque.
2. Tighten down all screws on main bearing caps with special tool 00 9 120 and torsion angle.

   Tightening torque, refer to 11 11 2AZ in ENGINE - TIGHTENING TORQUES .

   Fig 8: Identifying Torque Angle Measuring Dial

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Remove main bearing cap.

Read off main bearing play at width of flattened plastic thread with assistance of measurement scale.

Main bearing play, refer to ENGINE - TECHNICAL DATA - 645Ci .

• Remove plastic thread.
• Lubricate bearing shells and bearing shells.

Fig 9: Measuring Main Bearing Play Using Measurement Scale

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Tightening specifications for main bearing:

1. Tighten all screws on main bearing cover with jointing torque.
2. Unfasten screws on main bearing cover 5.
3. Strike back and front of crankshaft with plastic hammer to center guide bearing (do not damage crankshaft).

   Check axial play. Refer to ENGINE - TECHNICAL DATA - 645CI .

   Check guide bearing shell, crankshaft and crankcase if necessary.

4. Tighten screws of main bearing cover 5 with jointing torque.
5. Tightening torque, refer to 11 11 2AZ in ENGINE - TIGHTENING TORQUES .
   Fig 10: Checking Axial Using Dial Gauge

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Tighten down all screws on main bearing caps with special tool 00 9 120 and torsion angle.

Tightening torque, refer to 11 11 2AZ in ENGINE - TIGHTENING TORQUES .

Tighten down thread support bushings (2).

Tightening torque, refer to 11 11 3AZ in ENGINE - TIGHTENING TORQUES .

Fig 11: Locating Thread Support Bushings

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Replace flanged head screws (1) and tighten down.

Tightening torque, refer to 11 11 3AZ in ENGINE - TIGHTENING TORQUES .

Fig 12: Identifying Flanged Head Screws

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