11 21 531 Replacing all crankshaft main bearing shells (N20)

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

Special tools required:

00 2 590
11 4 470

Necessary preliminary tasks:

Remove CRANKSHAFT .

Check the position of the oil spray nozzles:

If the screw (1) is undone, the oil spray nozzle (2) must be readjusted.

Fig 1: Identifying Oil Spray Nozzle And Screw

Installation note:

Adjust oil spray (1) using a feeler gauge (2) in parallel to the crankcase.

Fig 2: Adjusting Oil Spray Using Feeler Gauge

Adjust feeler gauge to 0.40 mm.

Bring oil nozzle into contact with the feeler gauge by pressing lightly.

Tighten bolt (1).

Tightening torque: 11 11 3AZ.

Fig 3: Adjusting Feeler Gauge

Installation note:

Bearing shell (1) with lubricating groove must be fitted in upper section of crankcase.

Bearing shell (2) without lubricating groove must be installed in lower section of crankcase.

Fig 4: Identifying Bearing Shell Groove

Attention!

Allocation of bearing positions:

Bearing position 1 is at the front on the timing chain drive in the direction of travel.

Main bearing classification:

Code letters A/B or C) are used for the crankcase upper section.

Code letter (K) stands for clutch side.

Bearing seat assignment from 5 to 1, the first bearing position is on the timing chain drive.

Fig 5: Identifying Crankcase Upper Section Code Letters

Main bearing classification:

ID codes 1/2 or 3) are used for crankcase lower section.

Bearing seat assignment (1) from 1 to 5, the first bearing position is located on the timing chain drive.

NOTE: Code letters (2) are required exclusively for classifying CONNECTING ROD BEARING .

Fig 6: Identifying Connecting Rod Bearing Shells Code Letter

Observe bearing classification .

Installation note:

The letter/number combination produces a bearing shell pairing.

Identification by different colours.

Attention!

First bearing position is on the timing drive.

Engine damage will result if an insufficiently small radial clearance is determined.

If a large radial clearance is determined, this can lead to noises in crankshaft drive.

Code letters on crankcase:

Code letter A = bearing shell (1) colour Yellow with lubricating groove.

Code letter B = Bearing shell (1) in blue with lubricating groove.

Code letter C = bearing shell (1) colour Red with lubricating groove.

Code numbers on crankshaft:

Code number 1 = bearing shell (2) Yellow without lubricating groove.

ID code 2 = Bearing shell (2) in blue without lubricating groove.

Fig 7: Identifying Bearing Shell Groove

Code number 3 = bearing shell (2) Red without lubricating groove.

Attention!

The colour set yellow and red must not be installed, bearing colours blue/blue must be selected for this colour set.

Installation note:

Possible colour combinations for mounting the crankshaft in the crankcase.

Installation example:

For bearing 1 with the code letter C at the crankcase and the ID code 2 on the crankshaft, the bearing shell (1) in red is required for the top part of the crankcase and a bearing shell (2) in blue is required for the crankcase lower section (bedplate).

Fig 8: Identifying Bearing Shell Groove

Bearing 2: A and 2 in yellow and blue.

Bearing 3: C and 2 in red and blue.

Bearing 4: A and 1 colours Yellow and Yellow.

Bearing 5: C and 1 in blue and blue.

Attention!

The colour set yellow and red must not be installed, bearing colours blue/blue must be selected for this colour set.

(A 1 ) Crankcase/Yellow	(B 1 ) Crankcase/Blue	(C 1) Crankcase/Blue
(A 1 ) Crankcase lower section/Yellow	(B 1 ) Crankcase lower section/Yellow	(C 1) Crankcase lower section/Blue

(A 2 ) Crankcase/Yellow	(B 2 ) Crankcase/Blue	(C 2 ) Crankcase/Red
(A 2 ) Crankcase lower section/Blue	(B 2 ) Crankcase lower section/Blue	(C 2 ) Crankcase lower section/Blue

(A 3 ) Crankcase/Blue	(B 3 ) Crankcase/Blue	(C 3 ) Crankcase/Red
(A 3 ) Crankcase lower section/Blue	(B 3 ) Crankcase lower section/Red	(C 3 ) Crankcase lower section/Red