Removal and installation of a gear belt (DOHC)

Engines B6, BP (DOHC)

Removing

1. Disconnect the ground cable from the battery.

Attention! This erases the data from the engine fault memory or the radio's security code. Before disconnecting the battery, read the instructions in Section Removing and installing the battery.

2. Raise the vehicle and remove the right front wheel.

3. Remove the lower engine shield in the right wheel arch.

4. If equipped, remove the V-belt of the servo control pump and the air conditioning compressor, see Section Removing and installing/tensioning the V-belt.

5. Loosen the water pump pulley bolts.


6. Remove the alternator V-belt, see Section Removing and installing/tensioning the V-belt.

7. To turn out bolts of fastening of a belt pulley of the water pump and to remove a pulley.

Until 2/91, issue.

1. Block the crankshaft and unscrew the bolts securing the crankshaft belt pulley.

2. To block the crankshaft, turn on the 5th gear and ask the assistant to depress the brake pedal.

3. Remove the washer, crankshaft pulley, outer and inner toothed belt guide discs.

Since 3/91, issue.

1. Unscrew the bolts securing the crankshaft belt pulley. Hold the neck of the belt pulley with a special tool MAZDA SST 49D011102.

2. Remove the oil level dipstick.



3. Unscrew the top, middle and bottom toothed belt covers.

4. Remove the spark plugs, see Chapter Maintenance.

5. Set the piston of the 1st cylinder to the ignition position. To do this, turn the crankshaft so that the marks on the camshaft pulley match the marks on the timing cover.

6. To crank the crankshaft, engage 5th gear and move the vehicle on a level surface. Another possibility to turn the crankshaft: Raise the front wheel, shift into 5th gear and turn the wheel by hand.

Attention! After the piston of the 1st cylinder is in the ignition position, place the gearbox in the neutral position and once again check whether the marks on the crankshaft belt pulley and the timing gear cover match. If the marks match, in no case do not turn the crankshaft more.

7. If the old toothed belt is to be installed again, it should be marked. An arrow should be marked on the belt to indicate the direction of rotation. The crankshaft rotates in a clockwise direction.

8. Loosen the tensioning roller bolt and press the tensioning roller in the direction of the arrow until the toothed belt is loosened. Re-tighten the idler pulley bolt.

Attention! When wringing out the roller, put a rag on it so as not to damage the toothed belt or tension roller.

9. Remove the toothed belt, then do not change the position of the gear wheels.

Installation

Attention! Do not kink or twist the toothed belt. Replace dirty, damaged or worn toothed belt in any case. Check the uniformity and ease of movement of the tension roller.

Attention! If the camshaft turns with the toothed belt removed, neither piston should be at TDC. Otherwise serious damage to pistons and valves may occur. If you want to rotate the crankshaft, you must first set all the pistons to half height. To do this, mark a line with chalk on top of the crankshaft gear (condition: the crankshaft is in the TDC position of the piston of the 1st cylinder), then turn the crankshaft wheel 1/2 turn to the left or right. The chalk mark is in a horizontal position.

1. Make sure that the camshaft is in the position corresponding to the TDC of the 1st cylinder. In this case, the marks on the camshaft wheel and the marks on the cover of the timing mechanism drive must match.

2. Check whether the marks on the camshaft gear and cylinder block match.

3. Apply toothed belt so that the branch between the exhaust camshaft wheel and the crankshaft wheel is tensioned. If an old belt is installed, pay attention to the direction of its rotation.

Attention! When installing a toothed belt, the position of the camshaft and crankshaft must not change. Otherwise, serious malfunctions may occur in the engine, or the engine will not develop its maximum power.

4. Make sure that the camshafts are in the position corresponding to the TDC of the 1st cylinder. In this case, the marks on the camshaft gears must match with the marks on the cover of the timing mechanism drive and the cylinder head.

5. At the same time, the marks on the crankshaft gear and cylinder block must match. Then the engine is in the TDC position of the piston of the 1st cylinder.

6. Turn the crankshaft twice in the direction of rotation and once again check the coincidence of the marks, repeat the adjustment if necessary.




7. Turn the crankshaft in the direction of rotation to the tension mark, which is approximately 60 in front of the TDC mark.

8. Loosen the tension roller bolt so that the roller rests on the belt.

9. Tighten the tension roller mounting bolt with force 45 Nm.

10. Turn the crankshaft twice in the direction of rotation and check the adjustment again.

11. Check toothed belt tension. The toothed belt in the area between the two belt pulleys of the camshafts, when exposed to a force of 10 kg, which corresponds to pressing with your thumb, should bend by 9 - 11 mm. If the value does not meet the requirement, loosen the tension roller and tighten it again.

12. Screw on the upper, middle and lower toothed belt covers with force 10 Nm.



13. Install the outer and inner toothed belt guide discs according to the grooves on the crankshaft wheel. Observe installation position.

Until 2/91, issue.

1. Install the crankshaft belt pulley and washer and tighten the mounting bolts with force 15 Nm.

From 3/91 issue

1. Install the crankshaft pulley bolt. Holding the pulley neck with a special tool

2. MAZDA SST 49D011102 and tighten the bolt with force 165 Nm.

3. Install the water pump pulley and tighten the mounting bolts with hand force.

4. Install V-belt, see Section Removing and installing/tensioning the V-belt.

5. Tighten the water pump pulley firmly 10 Nm.

6. Install the spark plugs and connect the tips, see Chapter Maintenance.

7. Screw the shield into the right wheel well.

8. Insert oil dipstick.

9. Install the front wheel and lower the car.

10. Connect the mass cable to the battery.

11. If available, set the clock and set the radio security code.

12. Check the ignition timing, adjust if necessary, see Chapter Ignition system, Chapter Checking / adjusting the ignition timing.