11 21 531 Replacing all main crankshaft bearing shells (N62)
Special tools required:
- 00 2 590
- 00 9 120
(Engine Dismantled)
Clean components before installing.
Preparatory tasks are described in the section REPLACING CRANKSHAFT (N62/N62TU) OPERATION .
The letter (1) denotes the crankshaft construction stage.
S= Series
B= Construction stage 1
C= Construction stage 2
The numbers (2) denote the bearing shell classification for the relevant bearing position from 1 to 5 (main bearing cap).
1= yellow
2= green
3= violet
The letters (1) denote the bearing shell classification for the relevant bearing position from 1 to 5 in the crankcase and is located on the transmission side in the Vee. The first letter on the left applies to the first bearing position at the front.
Y= yellow
G= green
V= violet
Main bearing caps (4 and 5) are not identified.
Unscrew thread support bushings in main bearing caps.
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 rotate crankshaft.
Fit special tool 00 2 590 (Plastigage Type PG 1) to the oil-free crankshaft.
- Tighten all screws on main bearing cover with jointing torque.
- Tighten down all screws on main bearing caps with special tool 00 9 120 and torsion angle.
Tightening torque, see ENGINE - TIGHTENING TORQUES .
Remove main bearing cap.
Read off main bearing play at width of flattened plastic thread with assistance of measurement scale.
Main bearing play.
- Remove plastic thread.
- Lubricate bearing shells.
Do not wash off bolt coating.
No oil is permitted in the blind bores! (Danger of cracking).
Tightening specifications for main bearing:
- Tighten all screws on main bearing cover with jointing torque.
- Unfasten screws on main bearing cover.
- Strike back and front of crankshaft with plastic hammer to center guide bearing (do not damage crankshaft).
Check axial play.
Check guide bearing shell, crankshaft and crankcase if necessary.
- Tighten screws of main bearing cover 5 with jointing torque.
- Tightening torque, see ENGINE - TIGHTENING TORQUES .
Tighten down all screws on main bearing caps with special tool 00 9 120 and torsion angle.
Tightening torque, see ENGINE - TIGHTENING TORQUES .
Tighten down thread support bushings (2).
Tightening torque, see ENGINE - TIGHTENING TORQUES .
Replace flanged head screws (1) and tighten down.
Tightening torque, see ENGINE - TIGHTENING TORQUES .