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

(engine removed)

Necessary preliminary tasks:

Removing cylinder head. See 11 12 100 Removing and installing/replacing cylinder head (M52TU / M54 / M56)
Removing lower timing case cover. See 11 14 110 Removing and installing lower timing case cover (M52 / S52 / M52TU / M54)
Removing all pistons. See 11 25 671 Replacing piston rings on all pistons (M52 / S52 / M52TU / M54 / M56)
Remove end cover at rear; this operation is de section REPLACING CRANKSHAFT RADIAL SEAL .

Checking axial clearance:

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

Fig 1: Checking Axial Clearance

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Unfasten screw connection on reinforcement plates.

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.

Fig 2: Unfastening Screw Connection On Reinforcement Plates

Courtesy of BMW OF NORTH AMERICA, INC.

Unfasten screw connection on main bearing.

Remove main bearing caps (1 to 7).

Lever out crankshaft.

Fig 3: Removing Main Bearing Caps

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If necessary, release incremental gear.

Installation:

Replace screws.

Install screws and tighten down in two passes.

Tightening torque; 5.0 N.m plus 45°.

IMPORTANT: Check grinding stage of crankshaft.
Replace main crankshaft bearing shells. Replace conrod bearing shells. Replace grooved ball bearings in crankshaft.

Fig 4: Checking Grinding Stage Of Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.