Crankshaft Main Bearing: Service and Repair

11 21 531 - Replacing crankshaft main bearing shells W10





Special tools required:
- 00 2 590 00 2 590 Plastigage (5)
- 00 9 120 00 9 120 Torque Angle Measuring Dial





Important!
Replace all bolts in crankcase.

Do not wash off bolt coating.

There must be no oil in the blind holes (risk of cracking).





Necessary preliminary tasks:
- Remove engine.
- Remove gearbox .
- Remove cylinder head.
- Remove timing chain Service and Repair.
- Remove oil sump.
- Remove crankshaft radial seal.





Release screws (1).

Remove oil intake pipe (2).

Installation Note:
Replace O-ring (3).

Apply petroleum jelly to O-ring (3)





Undo crankcase bolts along the lines (2) shown, working from the outside towards the inside.

Undo crankcase bolts along the lines (1) shown, working from the outside towards the inside.

Note:
Use a plastic-headed hammer to release bottom section of crankcase.

Detach bottom section of crankcase.





Remove crankcase (1) by lifting up in direction indicated by arrow.

Important!
CAREFULLY place crankcase to one side Risk of breakage.

Installation Note:
Clean sealing surfaces.

Check fitted sleeves for damage and replace if necessary.





Installation Note:
Install main bearing shell with lubrication groove (1) in top section of crankcase.

Install main bearing shell without lubrication groove (2) in bottom section of crankcase.





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 twist crankshaft.

Place special tool 00 2 590 00 2 590 Plastigage (5) (Plastigage model PG 1) on oil-free crankshaft.





1. - Tighten down all bolts in crankcase to jointing torque.
2. - Tighten down all bolts in crankcase with special tool 00 9 120 00 9 120 Torque Angle Measuring Dial to torsion angle.

Installation Note:
Tightening torque 11 11 2AZ.





Remove crankcase.

Read off main bearing clearance with measuring scale.

Main bearing play.

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

Installation Note:
Always replace main bearing bolts.

Do not wash off bolt coating.

There must be no oil in the blind holes (risk of cracking).





Install bearing shells with lubrication groove (1) in top section of crankcase.

Installation Note:
Main bearing shell (2) is a thrust bearing and is mounted in the center of the upper section of the crankcase.

See illustration.





Installation Note:
Apply bead of sealing compound (1).

Apply Loctite liquid sealant 518 thinly and evenly to sealing surfaces.

See illustration.





Install crankshaft.

Mount bottom section of crankcase.

Fit screws 1 to 10.

Tightening torque: 11 11 1AZ.

Fit screws 11 to 20.

Tightening torque: 11 11 2AZ.





Checking axial clearance:

Push onto crankshaft (1) in direction of arrow with plastic hammer at rear and front in order to center guide bearing.

Axial clearance: refer to Technical Crankshaft and Bearings W10 / COOPER / B16 Data.





Assemble engine.