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.

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, 11 11 2AZ. Refer to ENGINE - TIGHTENING TORQUES .

   Fig 2: Tightening Screws On Main Bearing Caps

   Courtesy of BMW OF NORTH AMERICA, INC.

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 .

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

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 .

   Check guide bearing shell, crankshaft and crankcase if necessary.

4. Tighten screws of main bearing cover 5 with jointing torque.
5. Tightening torque, 11 11 2AZ. Refer to ENGINE - TIGHTENING TORQUES .
   Fig 4: Checking Axial Play

   Courtesy of BMW OF NORTH AMERICA, INC.

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

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

Tighten down thread support bushings (2).

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

Replace flanged head screws (1) and tighten down.

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