Weakening
The toothed belt mechanism has an automatic tensioner.
Unscrew the toothed belt cover see section 1.11.
Rotate the crankshaft clockwise and check the condition of the toothed belt.
Attention: The gearbox must be in position "neutral", and the handbrake is engaged. Turn the crankshaft with a socket wrench on the central bolt only clockwise.
Set the piston of cylinder 1 to the TDC position. To do this, turn the crankshaft so that the mark on the camshaft wheel coincides with the pointer.
Attention: the belt pulley must only be turned clockwise, otherwise the tension will not be set correctly. Do not turn the engine over the camshaft wheel, because this will overstress the toothed belt.
Loosen the locking screw of the toothed belt tensioner on the reverse side. This will require an extension wrench.
Press the belt tensioner down by hand to loosen the belt. In this position, tighten the clamping screw so that the tensioner is stationary.
Tension
Turn the crankshaft slightly in an anti-clockwise direction, namely so that the camshaft gear moves ½ tooth in the direction shown in the figure. This will compensate for the looseness of the toothed belt against the tensioning roller.
Loosen the clamping screw of the toothed belt tensioner so that it can turn on 1/6-½ turn. Thus, the tensioning roller spring exerts pressure on the toothed belt.
Also turn the crankshaft counterclockwise by 216 teeth of the camshaft wheel, as indicated by the arrow in the figure.
Tighten the clamping screw of the toothed belt tensioner to 50 Nm.
Turn the crankshaft clockwise and set the piston of the first cylinder to TDC.
Tension control
Press the toothed belt between the camshaft wheel and the injection pump gear with your index finger. The belt deflection should be 4-5 mm, otherwise, repeat the adjustment.
Screw on the toothed belt covers, see section 1.11.
Install the V-belt see paragraph 1.21.