11 31 025 Removing and installing/replacing intake camshaft (N55)

Special tools required:

11 4 481

Necessary preliminary tasks:

NOTE: All bearing caps are identified with numbers from 1 to 6.

The front bearing cap is a thrust bearing and does not have an identification.

Release screws on thrust bearing cover.

Release screws on all bearing caps 1 to 6.

Set all bearing caps down in special tool 11 4 481 in a neat and orderly fashion.

Fig 1: Camshaft Bearing Caps (N55)

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Remove intake camshaft (2) towards top.

Installation note:

Clean all bearing positions and lubricate with oil.

Check plain rectangular compression rings (1) for damage.

Fig 2: Removing Intake Camshaft

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Metal plain rectangular compression ring:

IMPORTANT: Plain rectangular compression rings (1) can easily break.

Only replace plain rectangular compression rings (1) when they are broken.

The plain rectangular compression rings have catches at the joint.

Press plain rectangular compression rings (1) apart upwards and downwards and removed towards front.

Fig 3: Pressing Plain Compression Rings Apart

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Make sure plain rectangular compression rings (1) can move freely.

Installation note:

When intake camshafts are inserted, no joint must point to a separating joint.

Plastic plain rectangular compression ring:

Installation note:

The plastic plain rectangular compression ring is maintenance free and does not have to be replaced.

Insert plastic plain rectangular compression ring (1) into groove of intake camshaft (2) (see arrow).

Lightly oil plastic plain rectangular compression ring (1) and rotate in direction of arrow until plastic plain rectangular compression ring (1) is positioned on the intake camshaft.

Fig 4: Rotating Plastic Plain Rectangular Compression Ring

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Check plastic plain rectangular compression ring (1 and 2) for freedom of movement.

Fig 5: Identifying Plastic Plain Rectangular Compression Ring

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IMPORTANT: Marks of intake and exhaust camshafts are different.
Mixing up the intake and exhaust camshaft will result in engine damage .
A Exhaust camshaft.
E Intake camshaft

Fig 6: Identifying Exhaust And Intake Camshaft

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Install intake camshaft so that the latch mechanism of the plain rectangular compression rings (1) does not point to a contact point of the bearing cap

Center latch mechanism of the plain rectangular compression rings with the bearing cap.

NOTE: Image of the exhaust camshaft.

Fig 7: Locating Plain Rectangular Compression Rings

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Insert intake camshaft so that data code (1) on mounting flats points upwards.

Fig 8: Identifying Data Code On Mounting Flats

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Position intake camshaft (1) so that cams point upwards at an angle and to the left.

Fig 9: Locating Intake Camshaft

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NOTE: All bearing caps are identified with numbers from 1 to 6.

The front bearing cap is a thrust bearing and does not have an identification.

Insert screws on all bearing caps 1 to 6.

Insert screws on thrust bearing cover.

Tightening torque 11 31 3AZ .

Fig 10: Camshaft Bearing Caps (N55)

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Assemble engine.