11 31 052 Replacing both timing chains (N47D20 K/U/O/T 1)

Special tools required:

Necessary preliminary tasks:

Remove ENGINE .
Mount engine on assembly stand. See MOUNTING ENGINE ON ASSEMBLY STAND (N47 D20 O1) .
Remove CYLINDER HEAD .
Removing OIL SUMP .
Remove GEAR CASE .

Attach special tool 11 4 320 for counter support on crankshaft.

IMPORTANT: Left-hand threads.

Release screw (1).

Remove camshaft sprocket (2) with timing chain for oil pump.

Fig 1: Identifying Screw And Camshaft Sprocket

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Remove timing chain for the cylinder head.

Remove tensioning rail (1) from cylinder head.

NOTE: Bearing journal (2) does not have to be removed.

Fig 2: Identifying Tensioning Rail And Bearing Journal

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The crankshaft must be blocked in order to release central bolt (1) of the high pressure pump.

Position special tool 11 4 320 with screw (2) at the crankcase.

Release central bolt (1) of high pressure pump.

IMPORTANT: Release central bolt only, do not remove.
Pistons of cylinder nos. 1 and 4 are at 45° after top dead center position.

Fig 3: Locating Special Tool (11 4 320)

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Screw special tool 11 8 740 into sprocket of high pressure pump.

Undo the central bolt (1) of the high pressure pump until the central bolt can rest on the special tool 11 8 740 .

Keep turning the central bolt (1) until the sprocket has come loose from the high pressure pump shaft.

Fig 4: Placing Central Bolt On Special Tool (11 8 740)

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Press chain tensioner in with tensioning rail (1) by hand in the direction of the arrow until the special tool 11 3 340 can be positioned.

Remove chain tensioner.

Fig 5: Pressing Chain Tensioner With Tensioning Rail

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Undo both bearing journals (1).

Remove guide rail (2).

Release bearing journal (4).

Remove tensioning rail (3).

Fig 6: Identifying Bearing Journals, Guide Rail And Tensioning Rail

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Release screw (1).

Remove special tool 11 4 320 .

Fig 7: Removing Special Tool (11 4 320)

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Remove impeller (1) with timing chain (2) from high pressure pump and crankshaft.

Remove timing chain (2).

Fig 8: Identifying Impeller And Timing Chain

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IMPORTANT: High pressure pump and crankshaft must be positioned to each other .

Fit timing chain (1).

Position crankshaft with special tool 2 285 671 (crankshaft is in the 11° top dead center).

Fix special tool 2 285 671 via the fitting bush on the crankcase.

Fig 9: Fitting Timing Chain

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Installation note:

To check the 11° after top dead center .

Pistons on cylinders 1 and 4 must be approx. 0.5 to 1 mm below the contact surface.

Fig 10: Measuring Distance Between Cylinders Pistons And Contact Surface

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Installation note:

Pay attention to the spline groove on the high pressure pump (1) (see arrow).

Fig 11: Locating High Pressure Pump

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Installation note:

The marking on the crankcase and the groove on the high pressure pump must be in line. (Graphic N57).

Fig 12: Locating Crankcase And Groove Marking On High Pressure Pump

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Installation note:

Spline and marking (0) on pinion are on a single plane.

Fig 13: Locating Spline And Pinion Marking

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Position impeller (1) with timing chain (2) on high pressure pump.

Marking (0) and cast lug must be in line.

Fig 14: Identifying High Pressure Pump Impeller And Timing Chain

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Insert central bolt (1) of high pressure pump.

Fig 15: Locating High Pressure Pump Central Bolt

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IMPORTANT: Clean all the threads of the bearing journals (if necessary with screw tap).

Position guide rail (2).

Screw in both bearing journals (1).

Tightening torque: 11 11 3AZ .

Position tensioning rail (3).

Screw in bearing journals (4).

Tightening torque: 11 11 3AZ .

Fig 16: Identifying Bearing Journals, Guide Rail And Tensioning Rail

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IMPORTANT: Clean sealing surfaces (1) with compressed air.

Fig 17: Identifying Sealing Surfaces

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Secure hydraulic chain tensioner (1) at bottom with two screws.

Tightening torque: 11 11 4AZ .

Remove special tool 11 3 340 .

Fig 18: Securing Hydraulic Chain Tensioner With Two Screws

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The crankshaft must be blocked in order to secure the central bolt (1) of the high pressure pump.

Position special tool 11 4 320 with screw (2) at the crankcase.

Secure central bolt (1) of high pressure pump.

Tightening torque: 13 52 2AZ .

Fig 19: Locating Special Tool (11 4 320)

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Position tensioning rail (1) with timing chain for cylinder head.

Fig 20: Identifying Tensioning Rail And Timing Chain For Cylinder Head

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Position timing chain with secondary sprocket wheel for oil pump.

Installation note:

Pay attention to mounting flats on oil pump shaft (1) (see arrow).

Fit special tool 11 4 320 .

Fig 21: Positioning Timing Chain With Secondary Sprocket Wheel For Oil Pump

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IMPORTANT: Left-hand threads.

Insert screw (1).

Tightening torque: 11 41 3AZ .

Fig 22: Identifying Screw

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Installation note:

Check fitting sleeves for damage.

Apply SEALING COMPOUND 2.2 along the housing (1) with a thickness of approx. 1.5 to 2 mm.

Fig 23: Checking Housing Thickness

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Mount GEAR CASE COVER .

Mount OIL SUMP with special tool 11 8 780 .

Fig 24: Identifying Gear Case Cover

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Installation note:

Flywheel must be installed to determined TDC.

Position flywheel.

Secure FLYWHEEL with special tool 11 9 260 .

Secure flywheel studs with special tool 11 4 180 .

Fig 25: Securing Flywheel With Special Tool (11 9 260)

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Turn flywheel (1) back.

Block crankshaft with special tool 11 5 320 in TDC firing position for cylinder 1.

Fig 26: Turning Flywheel

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Assemble engine.