11 21 500 Replacing crankshaft (M52 / S52 / M52TU / M54 / M56)

(engine removed)

Necessary preliminary tasks:

Remove cylinder head
Remove lower timing case cover
Remove all pistons, refer to 11 25 530 REMOVING AND INSTALLING OR REPLACING ALL PISTONS (M52 / S52 / M52TU / M54 / M56)
Remove end cover at rear; this operation is described in the section Replacing crankshaft radial seal. Refer to 11 14 151 REPLACING CRANKSHAFT RADIAL SEAL (TRANSMISSION SIDE) .

Checking axial clearance:

Fig 1: Checking Axial Clearance

Courtesy of BMW OF NORTH AMERICA, INC.

If permitted end float is exceeded, check crankshaft, guide bearing shells and engine block, replacing if necessary.

Unfasten screw connection on reinforcement plates.

Fig 2: Unfastening Screw Connection On Reinforcement Plates

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: The reinforcement plates are not fitted on engines with gray cast iron engine blocks or on engines with oil pumps integrated in oil scrapers.

Unfasten screw connection on main bearing.

Fig 3: Removing Main Bearing Caps

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Remove main bearing caps (1 to 7).

Lever out crankshaft.

If necessary, release incremental gear.

Installation:

Replace screws.

Install screws and tighten down in two passes.

Tightening torque 11 21 1AZ. Refer to ENGINE - TIGHTENING TORQUES .

IMPORTANT: Check grinding stage of crankshaft. Refer to ENGINE - TECHNICAL DATA .

Fig 4: Checking Grinding Stage Of Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.