Checking the tension of the toothed belt on a diesel engine
The belt deflection should be 4–5 mm.
1. Loosen the bolts securing the upper timing belt guard and remove the guard. Turn the crankshaft until the piston of the first cylinder is in the top dead center position. Since the head cover is removed, the position of the crankshaft must be controlled by the crankshaft belt pulley.
The notch on the crankshaft pulley should be positioned opposite the top dead center mark on the lower cover of the timing case.
To turn the crankshaft, place a spanner on the center bolt of the crankshaft belt pulley.
2. Loosen the belt tensioner mounting bolts by two turns.
3. Using a spanner, move the crankshaft clockwise from the top dead center position by two teeth of the camshaft toothed pulley. The tensioner spring begins to act and sets the belt to a new position.
4. Tighten the tensioner fastening. To prevent the timing belt tension from changing, first tighten the bolt in the slot, then the lower bolt. Tighten both bolts to a torque of 22–30 N·m.
5. To be sure, check the timing belt tension again. To do this, press your finger on the belt as shown in the picture. If the belt has a deflection of 4-5 mm, it is adjusted correctly and the removed parts can be installed.