Belt Drive, Dismantling

Dismantling the belt transmission

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

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 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 belt cover.

Removing the vibration damper





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

Removing the timing belt




There are two variants of the belt tensioner.
Up to engine number 3188688 the eccentric must be turned clockwise when loosening.
From engine number 3188689 the eccentric must be turned anticlockwise to loosen the belt tension.
Slacken off the centre screw for the belt tensioner slightly.
Hold the center screw in position and, depending on the model, turn the eccentric on the tensioner to 10 o'clock (clockwise) or 2 o'clock (anticlockwise) using a 6 mm allen key.
Remove the timing belt from the timing gear pulley for the camshafts.
Remove the timing belt.

Removing the crankshaft pulley





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

Caution! The crankshaft must not rotate!

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 oil pump




Remove the belt protection from the oil pump.
Remove the four oil pump screws.
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.

Checking the oil pump




Disassemble the oil pump.
Clean and check all components.
Check for damage and wear.
Replace the oil pump in the event of a fault.
Assemble the oil pump. Tighten to 6 Nm.

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 / 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 happen within 2 minutes in water at opening temperature.
Marking.90° C
Starts to open at.90°C
Fully open at.105°C