Removal
Fixing the camshaft from turning with a wrench by the chamfer on the rear part of the camshaft
Unscrewing the camshaft sprocket mounting bolt
Removal the sprocket from the camshaft
1. Remove the air filter.
2. Remove the fan impeller and radiator fan shroud.
3. If equipped, remove the rear self-leveling suspension pump and move it to the side without disconnecting the hoses from it.
4. Remove the cylinder head cover.
5. Turn the engine crankshaft and set the piston of the first cylinder to the top dead center. Check that all the timing marks are aligned with the pointers.
6. Remove the drive chain tensioner mechanism.
7. Using paint, make an alignment mark on the camshaft sprocket and timing chain link.
8. Using a wrench, secure the camshaft from turning by the chamfer at the rear of the camshaft and unscrew the camshaft sprocket mounting bolt (see fig. Fixing the camshaft with a wrench from turning by the chamfer on the rear part of the camshaft, Unscrewing the bolt securing the camshaft sprocket).
9. Remove the sprocket from the camshaft and remove it from the drive chain. Keep the chain taut at all times to prevent it from coming off the intermediate shaft sprocket or crankshaft (see fig. Removing the sprocket from the camshaft).
10. Remove the woodruff key from the camshaft.
Examination
1. Check the condition of the teeth on the sprocket. The teeth on the sprocket are symmetrical and if the teeth on one side are worn out, the sprocket must be replaced.
Installation
1. Install the woodruff key into the camshaft groove.
[Article borrowed from the web portal mercedesman.ru]
2. Check that the timing marks on the camshaft and crankshaft are aligned with the pointers. When installing a new sprocket, mark it in the same location as the old sprocket.
3. Insert the sprocket into the chain according to the marks made earlier.
4. Install the sprocket onto the camshaft. On single-row chain models, the sprocket hub protrusion should face the camshaft, and on double-row chain models, the curved side of the sprocket should face the camshaft.
5. Secure the camshaft from turning and screw in the sprocket mounting bolt, tightening it to the required torque.
6. Install the drive chain tensioner mechanism.
7. Using the crankshaft pulley bolt, rotate the engine crankshaft two full revolutions and check that all timing marks are aligned with the pointers. If not, remove the sprocket from the camshaft and move the chain one tooth on the sprocket.
8. Install the cylinder head cover.
9. Install the rear self-leveling suspension pump.
10.Install the fan impeller and shroud.
11. Install the air filter.