A shift of one tooth on the camshaft sprocket corresponds to 18° of crankshaft rotation. A shift of the spline to the right in the direction of rotation ensures earlier opening of the intake valve, and a shift to the left ensures later opening of the intake valve. Fig. 97 clearly shows the change in valve timing.
Fig. 97. Adjusting the valve timing.
Position A - early opening,
position B - late opening.
While holding the camshaft from turning, loosen the mounting bolt.
Remove the sprocket from the camshaft.
Install the required key and put the sprocket on.
Information copied from the website: Mercedesman.ru
Repeat the valve timing check.
After replacing the key or installing a new drive chain, adjust the ignition timing. The camshafts rotate in opposite directions, which must be taken into account when installing the keys.