Timing belt and camshaft.
The toothed belt is an important component of the timing system. Its task is to drive the timing thread. It is located outside the crankcase and is located on the camshaft and crankshaft gears. The gear ratio of the drive is 2:1, i.e. the camshaft rotates twice as slowly as the crankshaft. The belt is made of plastic reinforced with steel wires and requires neither lubrication, nor tightening. Volkswagen requires replacement of the timing belt on the engines 1,9 TDI co 90000 km, and in the V6 engine co 120000 km. Replacing the toothed belt is not only laborious, but also a very difficult activity. After replacement, it is necessary to adjust the timing system. It requires, beyond knowledge, many specialized tools (m.in. GMP setting device, setting ruler, gripper with feet, Matra nut wrench). In diesel engines, it is also necessary to set the injection start in the injection pump, as the toothed belt also drives the pump. Incompetent replacement of the toothed belt leads to the most severe damage to the engine. Therefore, this task must be entrusted to a workshop.