Dismantling the Belt Drive

Belt drive, dismantling

Special tools:
999 5304 SEPARATOR 999 5304 Separator
999 5433 COUNTERHOLD 999 5433 Counterhold
999 5747 Socket 999 5747 Socket

Note! As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information in the illustrations is always correct.

Aligning the engine according to the marking




Install the upper timing belt cover.
Turn the crankshaft clockwise until the markings on the crankshaft belt pulley and the timing belt pulley are aligned with the markings on the oil pump and the upper timing belt cover.
Remove the upper timing cover.

Removing the vibration damper




Remove the 4 screws. Use the crankshaft center nut as a counterhold.
Install counterhold 999 5433 COUNTERHOLD 999 5433 Counterhold. Remove the center nut.
Remove counterhold 999 5433 COUNTERHOLD 999 5433 Counterhold.
Work the vibration damper loose.

Removing the timing belt




Slacken off the center screw for the belt tensioner slightly.
Hold the center screw in place. Turn the belt tensioner eccentric clockwise to 10 o'clock using a 6mm Allen key.
Remove the timing belt from the timing gear pulley for the camshafts.
Remove the timing belt.

Removing the crankshaft pulley





Caution! The crankshaft must not rotate.

Use puller 999 5304 SEPARATOR 999 5304 Separator and two 45 mm M8 screws with washers.
Pull off the timing gear pulley.

Removing the belt tensioner and idler pulley




Remove the belt tensioner and idler pulley.
Check the rolling surface and the bearings.
Check for any noise. Check for any play in the bearings.
Check that the rolling surfaces are smooth and clean.

Removing the oil pump




Remove the belt protection from the oil pump.
Remove the 4 screws for the oil pump.
Carefully work the oil pump out. Use a groove-cut chisel with stop lugs.
Carefully draw the oil pump past the end of the crankshaft.
Carefully clean the gasket face and mating surfaces.
Remove tool 999 5747 Socket 999 5747 Socket.

Checking the oil pump




Unscrew the oil pump. Note the position of the outer/inner pump wheel and the piston/spring for the relief valve.
Clean and check all components.
Check for damage and wear. Replace the oil pump in the event of a fault.
When replacing the sealing ring.
Carefully tap the sealing ring out. Use a carefully selected drift and hammer.
A new sealing ring is first installed after the pump has been installed in the cylinder block.

Assembling the oil pump




Place the inner and outer pump wheels in the oil pump housing.
The inner pump wheel has a inset surface around the hole for alignment to the crankshaft. The inset surface should be positioned towards the sealing ring in the oil pump housing.
Install the spring and piston for the relief valve. Screw the pump together. Tighten the screws. See: Tightening torque Tightening Torque.

Removing the coolant pump/timing belt cover




Remove the screws.
Carefully tap the pump pulley with a rubber mallet.
Work the pump loose.
Carefully clean the gasket face and mating surfaces.
Remove the inner timing belt cover.

Removing the thermostat and thermostat housing
Remove the cover over the thermostat (Tx40).
Lift out the thermostat
Remove the hose for the water heated crankcase ventilation.
Remove the thermostat housing from the cylinder head.
Carefully clean the gasket face and mating surfaces.
Remove the fuel pressure line.

Checking the opening function of the thermostat




The thermostat can be tested in warm water.
Maximum opening must occur within 2 minutes in water at opening temperature.
Marking.90° C
Starts to open at.90°C
Fully open at.105°C