Replacing Timing Belt
Replacing timing belt
Special tools:
998 8500 BELT TENSION GAUGE 998 8500 Belt Tension Gauge
999 5456 COMPRESSION TOOL 999 5456 Compression Tool
Remove:
- spark plugs cover
- two fuel lines clamps
- lift up expansion tank and place over engine to one side
- front timing cover
- auxiliaries belt
Position camshafts/crankshaft according to marking
Remove right front wheel and slacken off fender liner slightly.
Remove vibration damper heat shield.
The camshaft pulleys should rotate until all the markings correspond.
Check measure the belt tension
Wait 5 minutes after aligning the timing belt.
Position measuring instrument 998 8500 BELT TENSION GAUGE 998 8500 Belt Tension Gauge between the exhaust camshaft pulley and the coolant pump.
Read the value using a mirror. The measuring instrument must not be removed before the reading is made.
For the 21 mm belt, the tension must be within the range of 3.5 - 4.6 units.
If the above values are not obtained the tensioner damping unit must be replaced.
Removing timing belt
Hold tensioner damping unit upper screw.
Slacken off the lower screw.
Turn the tensioner damping unit so that the pulley comes free.
Remove:
- the lower screw
- tensioner damping unit
- upper timing cover
- timing belt
Greasing the bushing
Engines with automatic timing belt tensioners should have the lever bushing greased every time the belt is changed or the tension pulley removed. The lever arm must be greased so that the bearing does not stick and give the wrong tension.
Remove:
- Tension pulley lever screw
- Tension pulley
- Sleeve behind screw
Grease the surfaces on the lever bushing, the screw and the sleeve with grease P/N. 11 61 246-2 (50g) or 11 61 247-0 (500g).
Install:
- Sleeve
- Tension pulley
- Tension pulley lever screw
Tighten the screw to 39 ± 5 Nm .
Check tensioner and idler pulleys
Spin the pulleys and listen for noise in the bearings.
Check that the tensioner pulley actuator arm has not seized in its bearing. Check the idler pulley and tensioner pulley are tightened correctly.
Adjusting the mechanical belt tensioner
If a mechanical belt tensioner is being used, adjust according to Adjusting the mechanical belt tensioner, B5234T9, B5244T7 Adjustments.
Lock tensioner damping unit
Check that there is no visible leakage.
Compress the tensioner damping unit with tool 999 5456 COMPRESSION TOOL 999 5456 Compression Tool. Position tensioner damping unit in the tool and screw tool center nut to the bottom. Wait until compression is complete and install a 2 mm lock pin in the piston.
Note! If there is leakage or no resistance when pushed in or if it cannot be pushed in the tensioner damping unit must be replaced.
Install the new timing belt
Install the tensioner damping unit, torque tighten to 25 Nm .
Place belt around crankshaft and right idler pulley.
Place belt over camshaft pulley.
Position belt around coolant pump and press the belt over the tensioner pulley.
Installing camshaft pulley and timing belt
Caution! The timing belt must be installed correctly to obtain the correct timing. Before tightening the screws between the camshaft and camshaft pulley press hard (or hit with a plastic mallet) twice on the belt between the camshafts and then twice on the belt between the exhaust camshaft and the engine coolant pump. Do this to ensure that the gears mesh with the timing gear pulleys.
Secure drive belt
Press hard or knock the belt twice in the direction of arrow (1) and twice in the direction of arrow (2) using a rubber mallet.
Secure camshaft pulleys
Tighten the camshaft screws (2 x 3) to 20 Nm.
Turn the engine crankshaft two turns
Pull the lock pin out of the tensioner/damping unit.
Position the upper timing cover.
Turn crankshaft two revolutions and check that the markings on the crankshaft and camshaft timing gear pulley align.
Install:
- two fuel lines clamps
- front timing cover
- auxiliaries belt
- spark plugs cover
- expansion tank
- vibration damper protective panel
- fender liner, wheel
Test function
Test drive engine.