Connecting Rod Bearing: Service and Repair

11 24 571 - Replacing all connecting rod bearings (N54)





Special tools required:
- 00 2 590 00 2 590 Measurement Aid
- 00 9 120 00 9 120 Torque Angle Measuring Dial





Important!
All crank pins are connected with the crankshaft.

Blue / Red bearing shell colours are no longer used in combination.





Necessary preliminary tasks:
- Remove all pistons Service and Repair.





Important!
All crankshaft crank pins are classified.

Bearing shell colours are different in connecting rod and in connecting rod bearing cap.

Possible classifications per connecting rod at top and bottom:

r:

Connecting rod = Yellow.
Connecting rod bearing cap = Red.

b:

Connecting rod = Violet.
Connecting rod bearing cap = Blue.
Only one colour may be fitted per connecting rod and connecting rod bearing cap.

In direction of arrow from (1 to 2) crank pin (1 to 6).

Example:
Possible classification: rbbrrb.

Cyl. 1: - Classification r= rod side Yellow bearing cap side Red.
Cyl. 2: - Classification b= rod side Violet bearing cap side Blue.
Cyl. 3: - Classification b= rod side Violet bearing cap side Blue.
Cyl. 4: - Classification r= rod side Yellow bearing cap side Red.
Cyl. 5: - Classification r= rod side Yellow bearing cap side Red.
Cyl. 6: - Classification b= rod side Violet bearing cap side Blue.





Install new conrod bearing shells.

In each case insert only one colour of bearing shell (1 and 2) for each conrod.





Check conrod bearing clearance.

Piston in BDC position.

Fit special tool 00 2 590 (Plastigage Type PG 1) to oil-free crankshaft.

Fit bearing cap so that pairing letters match up.





Important!
Do not distort conrods or crankshaft.

Use the old conrod bolts to check conrod clearance.

Tighten down conrod bolts with special tool 00 9 120.

Tightening torque 11 24 1AZ. Mechanical Specifications





Remove bearing cap. Read off bearing clearance at width of crushed plastic thread with aid of measuring scale.

Conrod bearing clearance. Mechanical Specifications

- Remove plastic thread.
- Coat crankshaft and bearing shells with oil.
- Install new conrod bolts and tighten down with special tool 00 9 120.
Tightening torque 11 24 1AZ. Mechanical Specifications





Assemble engine.