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

WARNING: This page is about a different car, the 2005 BMW Z4, 2004 BMW Z4, and 2003 BMW Z4. However, it is still accessible from the selected car via links, so may be relevant.

(engine removed)

Necessary preliminary tasks:

Removing cylinder head
Removing lower timing case cover
Removing all pistons
Remove end cover at rear; this operation is described in the 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

G03297128

Courtesy of BMW OF NORTH AMERICA, INC.

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: Removing Screw Connection On Reinforcement Plates

G03297129

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

G03297130

Courtesy of BMW OF NORTH AMERICA, INC.

If necessary, release incremental gear.

Installation:

Replace screws.

Install screws and tighten down in two passes.

Tightening torque, see 11 21 1AZ in ENGINE - TIGHTENING TORQUES .

IMPORTANT: Check grinding stage of crankshaft.

Fig 4: Checking Grinding Stage Of Crankshaft

G03297131

Courtesy of BMW OF NORTH AMERICA, INC.

Replace main crankshaft bearing shells . See .11 21 531 Replacing All Main Crankshaft Bearing Shells (M52 / S52 / M52TU / M54 / M56)

Replace conrod bearing shells . See 11 24 571 Replacing all connecting rod bearings (M52 / S52 / M52TU / M54 / M56) .

Replace grooved ball bearings in crankshaft . See 11 21 571 Replacing Grooved Ball Bearing In Crankshaft (M52 / S52 / M52TU / M54 / S50 / S54) .