11 24 571 Replacing all connecting rod bearing shells (N20)

WARNING: This page is about a different variant/trim than selected.

Special tools required:

00 2 590
00 9 120
83 30 0490 190
83 30 0 490 504

IMPORTANT: Modified procedure:
All crank pins are connected with the crankshaft.
The Blue/Red connecting rod bearing shell colours are no longer fitted in combination.

Necessary preliminary tasks:

Remove OIL SUMP .

IMPORTANT: All crankshaft crank pins are classified.
The identification (2) is located on the first crank web.
The first code letter (2) from the left is the first cylinder towards the control chain side

Fig 1: Identifying Connecting Rod Bearing Shells Code Letter

Optional classifications (2) per connecting rod

On the connecting rod and connecting rod bearing cap:

r. Connecting rod = Yellow.

Connecting rod bearing cap = Red.

b. Connecting rod = Violet.

Connecting rod bearing cap = Blue

Example:

Possible classification: b r r r

Zylinder1: Classification b

Violet (connecting rod)/\Blue (connecting rod bearing cap)

Zylinder2: Classification r

Yellow (connecting rod)/Red (connecting rod bearing cap)

Zylinder3: Classification r

Yellow (connecting rod)/Red (connecting rod bearing cap)

Zylinder4: Classification r

Yellow (connecting rod)/Red (connecting rod bearing cap)

Release connecting rod bolts (1).

Remove connecting rod bearing cap (2).

Fig 2: Identifying Connecting Rod Bearing Cap And Bolts

IMPORTANT: Risk of damage to cylinder wall and to crankshaft.

Gently release connecting rod from crankshaft.

Remove connecting rod bearing shells (1 and 2).

Use new connecting rod bearing shells according to code letter.

Fig 3: Identifying Connecting Rod Bearing Shells

Installation note:

Pay attention to guide lugs during installation.

IMPORTANT: All crankshaft crank pins are classified.

If the connecting-rod bearing must be checked:

Piston in BDC position.

To determine the connecting rod bearing play, make sure that the bearing positions are clean and free from oil and grease.

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

Fit connecting rod bearing cap so that pairing letters match up.

Order number:83 30 0490 190

Fig 4: Locating Bearing Cap Pairing Letters

IMPORTANT: Do not distort connecting rods or crankshaft.

It is possible to use the old connecting rod bolts if the connecting-rod bearing play requires checking.

Tighten down connecting rod bolts with special tool 00 9 120 .

Tightening torque 11 24 1AZ .

Order number:83 30 0 490 504

Fig 5: Tightening Connecting Rod Bolts With Special Tool (00 9 120)

Unscrew connecting rod bearing cap. Read off connecting rod bearing play at width of flattened Plastigage on measurement scale.

CONNECTING ROD BEARING PLAY.

Remove Plastigage
Coat crankshaft and connecting rod bearing shells with oil
Install new connecting rod bolts and tighten down with special tool 00 9 120 .

Tightening torque 11 24 1AZ .

Fig 6: Checking Connecting Rod Bearing Play

Assemble engine.