Replacing both timing chains (B48 and B46 engine) (Cooper S and John Cooper Works)

Special tools required:

2 357 904
11 4 120

Preliminary work needed:

Remove ENGINE with transmission
Vehicles with automatic transmission: Remove transmission.
- Up to model year 2019, refer to REMOVING AND INSTALLING TRANSMISSION (AISIN F21FT) .
- As of model year 2020, refer to REMOVING AND INSTALLING AUTOMATIC TRANSMISSION (AISIN GA8G45) .
Vehicles with manual transmission: Remove transmission.
- Refer to REMOVING AND INSTALLING TRANSMISSION (GS6-59BG/DG) (COOPER S AND JOHN COOPER WORKS) .
Mount ENGINE ON ASSEMBLY JIG .
Remove FLYWHEEL .
Remove CYLINDER HEAD .
Remove VACUUM PUMP .
Remove REAR TIMING CASE COVER .

Removal:

Remove drive chain (1) for oil pump.

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Remove camshaft timing chain (1).

Remove tensioning rail (2) from bearing journal (3).

NOTE: Bearing journal (3) does not have to be removed.

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

Position crankshaft with guide pin. Fix special tool 2 357 904 with screw (2) in position at the crankcase.

Release central bolt (1).

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Use screwdriver (2) to press piston (3) for chain tensioner to stop and secure piston with special tool 11 4 120.

Unscrew the screws (1). Remove chain tensioner.

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Undo both bearing journals (1).

Remove guide rail (2).

Release bearing tappet (4).

Remove tensioning rail (3).

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Release screw (1) and remove camshaft wheel (2).

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Release screw (2) and remove special tool 2 357 904.

Remove timing chain (1).

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Installation:

Fit timing chain (1).

Position crankshaft with special tool 2 357 904.

Fix special tool 2 357 904 with screw (2) in position at the crankcase.

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

Parts: Replace bearing journals.

Install camshaft wheel and tighten screw until it makes contact.

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 .

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

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Install hydraulic chain tensioner. Tighten down screws (1).

Tightening torque: 11 11 7AZ .

Secure piston (3) for chain tensioner with screwdriver (2).

Remove special tool 11 4 120 and slowly remove screwdriver (2).

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NOTE: The crankshaft must remain blocked in order to tighten the central bolt (1) of the high pressure pump.
Parts: Replace central bolt (1).

Tighten down central bolt (1).

Tightening torque: 11 11 4AZ .

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Install tensioning rail (2) with timing chain (1) for camshafts.

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Mount drive chain (1) for oil pump on crankshaft.

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Required follow-up work:

Install REAR TIMING CASE COVER .
Install VACUUM PUMP .
Mount the FLYWHEEL .
Mount the CYLINDER HEAD .
Remove engine from ASSEMBLY JIG .
Install transmission. Refer to REMOVING AND INSTALLING TRANSMISSION (AISIN F21FT) (up to model year 2019) or REMOVING AND INSTALLING TRANSMISSION (GS6-59BG/DG) (as of model year 2020).
Install ENGINE with transmission