Harmonic Balancer - Crankshaft Pulley: Service and Repair
Removing and installing belt pulley for crankshaft
Caution: Never work on a hot engine as contact with hot components can cause injury!
Removing belt pulley
Note;
- When removing and refitting air cleaner housing, ensure that rubber plugs for fixing the housing do not fall out.
1. Remove air cleaner housing. Undo screw-type hose clamp on throttle body and the M8 fastening screw. Pull off cable plug for the mass air flow sensor and remove air cleaner housing.
2. Release drive belt. To do this, turn the tensioning roller clockwise at the hexagon of the tensioning lever and remove the drive belt at the deflection roller below the generator.
Note;
- Wrap a cloth or similar around the mounting lever to avoid damaging the body paintwork.
- Observe precautionary measures when using oxygen sensors! Damage or soiling of the oxygen sensor cables or plug connections may cause a malfunction.
3. Release oxygen sensor plug at the disconnection point in the engine compartment on the left and right and unclip. Release oxygen sensor cable from cable holders and, together with the plug, guide it past the engine carrier and down towards the catalytic converter. To do this, gently press the engine carrier with a mounting lever towards the belt pulley -arrows-. On cylinder side 1-3, release the black oxygen sensor cable from the sheet metal bracket.
Note;
- To remove and install the catalytic converters the assistance of a second person is recommended!
- Before unscrewing, spray the screw connections of the exhaust system with penetrating oil. If the joints are severely corroded, the application of heat is helpful.
- When removing catalytic converters, make sure that oxygen sensors, cables and plugs are not damaged.
4. Remove catalytic converters. Undo the clamp screws -Item 2- at the joints to the rear muffler on the left and right. Unscrew each of the three fastening nuts for the exhaust manifold flange -Item 1-. Undo the clamp screws for the holder on the engine carrier -Item 3- and push the clamps over the holder.
5. Before removal, mark position of clamps at joint with rear muffler (e.g. with a touch-up applicator). Then, gently tapping with an aluminum mandrel, move them towards the muffler -arrow-.
6. Then press the flange of the catalytic converter at the exhaust manifold pipe out of the studs and simultaneously pull the two catalytic converters out and downwards -arrows-.
7. Turn belt pulley clockwise until the two locating bores for the holding wrench 9548 are horizontal. In this position, the special tool can be used between the fastening nuts for the engine carrier -see figure-. Making use of the nuts as a backstop for the tool reduces the effort required to undo and tighten the belt pulley screw.
Note;
- When undoing and tightening the belt pulley screw, the assistance of a second person to hold the special tool is recommended!
8. Undo the collar screw on the belt pulley. To counter, position the special tool holding wrench 9548 against the right fastening nut of engine carrier and hold it there. As the torque required to release the screw is greater than to tighten it, a tool with a long lever arm should be used to release it. Now unscrew the collar screw and remove the belt pulley together with friction plate.
Installing belt pulley
Note;
- Check friction plate and straight pin for signs of damage and replace if necessary.
- Replace collar screw M14 x 1.5.
- The parts to be screwed together must be clean, dry and free of grease; if necessary, clean with solvent naphtha or acetone.
1. Position friction plate on straight pin of belt pulley (fitted bore for straight pin) and fit belt pulley to crankshaft journal using a new collar screw. Loosely pre-position drive belt on the belt pulley.
View of belt pulley and friction plate from crankshaft
2. Tighten M14 collar screw with torque wrench. To do this, fit holding wrench 9548 to the belt pulley and position against the left fastening nut of engine carrier to counter.
Tightening torque 250 Nm (185 ft. lbs.)
Note;
- Always replace the clamps at the joints with the rear mufflers.
- Always replace the fastening nuts at the catalytic converter/exhaust manifold flange.
- Always replace the flange seals between catalytic converter and exhaust manifold.
- Before tightening screw connections of catalytic converters, first do up all nuts and bolts evenly to obtain a fastening that is as free of tension as possible.
- When inserting catalytic converters, make sure that oxygen sensors, cables and plugs are not damaged.
3. Install the two catalytic converters. Replace clamps between catalytic converter and rear muffler. Replace fastening nuts for flange connection to exhaust manifold and replace flange seal. Tighten screw connections to the specified tightening torque.
Tightening torques:
1. Fastening nuts for catalytic converterhaust manifold flange: 23 Nm (17 ft. lbs.)
2. Clamp screws: 46 Nm (34 ft. lbs.)
3. Clamp screw for holder on the engine carrier: 17 Nm (13 ft. lbs.)
4. Route oxygen sensor cable with plug past engine carrier to the disconnection points in the engine compartment. To do this, gently press the engine carrier with a mounting lever towards the engine so that the plug can be led between the body and the engine carrier.
5. Fit and tension the drive belt.
6. Install air cleaner housing.
Tightening torques
Collar screw, belt pulley M14 x 1.5 250 Nm (185 ft. lbs.)
Fastening nut, catalytic converter flange M8 23 Nm (17 ft. lbs.)
Clamp screw, catalytic converter M10 46 Nm (34 ft. lbs.)
Clamp screw, holder to engine carrier M8 17 Nm (13 ft. lbs.)
Screw, air cleaner to body M8 23 Nm (17 ft. lbs.)