Checking main bearing clearance:

Do not twist crankshaft.

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

Fig 1: Checking Main Bearing Clearance

Courtesy of BMW OF NORTH AMERICA, INC.

Position main bearing caps (1 to 5) so that retaining grooves of main bearing shells are on one side.

Align main bearing cap flush with side of bearing seat.

Fig 2: Aligning Main Bearing Cap Flush With Side Of Bearing Seat

Courtesy of BMW OF NORTH AMERICA, INC.

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

No oil is permitted in the blind bores (danger of cracking).

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

Tightening Torque,

refer to 11 11 2AZ in ENGINE - TIGHTENING TORQUES

Fig 3: Tightening Main Bearing Cap Bolts With Special Tool 00 9 120

Courtesy of BMW OF NORTH AMERICA, INC.

Remove main bearing cover and read off main bearing clearance from thickness of crushed plastic thread with the help of the measuring scale.

Main bearing clearance,

refer to ENGINE - TECHNICAL DATA - X5

Fig 4: Measuring Main Bearing Clearance

Courtesy of BMW OF NORTH AMERICA, INC.

Remove plastic thread.

Lubricate crankshaft and main bearing shells.

Position main bearing caps (1 to 5) so that retaining grooves of main bearing shells are on one side.

Align main bearing cap flush with side of bearing seat.

Fig 5: Aligning Main Bearing Cap Flush With Side Of Bearing Seat

Courtesy of BMW OF NORTH AMERICA, INC.

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 thrust bearing (do not damage crankshaft).
4. Tighten screws of main bearing cover 5 with jointing torque.
5. Tighten down all bolts on main bearing cap with special tool 00 9 120 with torsion angle.

For Tightening Torque,

refer to 11 11 2AZ in ENGINE - TIGHTENING TORQUES

Fig 6: Tightening Main Bearing Cap Bolts With Special Tool 00 9 120 With Torsion Angle

Courtesy of BMW OF NORTH AMERICA, INC.

Check axial play.

Axial play,

refer to Technical Data in ENGINE - TECHNICAL DATA - X5

Check guide bearing shell, crankshaft and crankcase if necessary.

Fig 7: Checking Axial Play

Courtesy of BMW OF NORTH AMERICA, INC.

Tighten threaded protective bushes.

Tightening Torque,

refer to 11 11 3AZ in ENGINE - TIGHTENING TORQUES

Fig 8: Tightening Threaded Protective Bushes

Courtesy of BMW OF NORTH AMERICA, INC.

Replace collar screws.

Tighten taper screw mount on main bearing (collar screws and spacer pins).

Tightening Torque,

refer to 11 11 3AZ in ENGINE - TIGHTENING TORQUES

Fig 9: Tightening Taper Screw Mount On Main Bearing (Collar Screws And Spacer Pins)

Courtesy of BMW OF NORTH AMERICA, INC.