Withdrawal
Note. If there are extraneous noises emitted during the operation of the timing belt, first of all check the adjustment of its tension. This procedure can be done without removing the front covers (see paragraph 5 of Section Removal, condition check and installation of cogwheels and a belt of a drive of balancing shafts).
1. Bring the engine to the TDC position of the first cylinder and, in order to provide access to the timing belt, remove the front covers and the balancing shaft drive belt (see Section Bringing the piston of the first cylinder to the top dead center position (TDC)).
2. With the tensioner nut loose, press the tensioner roller down, then tighten the nut. Now the timing belt can be thrown off the timing gears.
Note. If the old belt is in good condition and will be installed in place, mark with chalk or white paint the direction of its rotation and position relative to the gears of the shafts.
3. If necessary, the camshaft gear can be removed - insert a large screwdriver into the hole in the wheel casting, then carefully loosen the mounting bolt with a socket wrench.
Attention! Try to prevent the camshaft from turning while releasing the bolt of its gear!
4. Removing the gear wheel will provide access to the two bolts securing the rear belt cover, as well as to the camshaft oil seal.
Examination
Manually check for freedom of rotation of the tensioner pulley, then jerk it from side to side, checking for play in the bearing. Check the condition of the timing gear teeth (pay attention to the presence of chips, cracks and other mechanical damage). Assess the amount of axial play of the camshaft. Carefully inspect the timing belt on both sides, checking it for signs of wear (especially resistant tooth walls), cracks, cuts, abrasions and traces of oiling. Replace defective components.
Note. Take this opportunity to replace the water pump at the same time (see chapter Cooling, heating systems).
Installation
1. If removed, reinstall the camshaft gear and tighten the bolt of its fastening with the required force.
2. Make sure the engine is still at TDC at the end of the compression stroke of the first cylinder (see Section Bringing the piston of the first cylinder to the top dead center position (TDC)).
3. Get alignment marks on the gear wheels of the camshaft and crankshaft with the mating marks on the engine block.
Note. The marks on both sides of the camshaft pulley must be aligned with the top cut of the cylinder head.
4. Make sure the rear balance shaft is locked with a 6 x 100 mm bolt or bar wrench. Place the timing belt over the gears in a counterclockwise direction in the following order: crankshaft wheel, tensioner, water pump, camshaft wheel.
5. Loosen the tensioner nut to tighten the belt. Tighten the nut and install the balance shaft drive belt (see Section Removal, condition check and installation of cogwheels and a belt of a drive of balancing shafts).
6. Adjust the tension of both belts (see Section Removal, condition check and installation of cogwheels and a belt of a drive of balancing shafts), rotate the crankshaft by its pulley bolt two full turns, stopping it again at the TDC position of the end of the compression stroke of the No. 1 cylinder. Make sure all alignment marks are back in their original positions. Re-adjust belt tension (see paragraph 5 of Section Removal, condition check and installation of cogwheels and a belt of a drive of balancing shafts).
7. Further installation is carried out in the reverse order to the dismantling of the components. When installing the crankshaft pulley, do not forget to lubricate the threads and the lower surfaces of the heads of its mounting bolts.
Note. Do not use an impact wrench to tighten the pulley bolt.