Remove the radiator and fan.
In cars with air conditioning, remove the compressor together with the pipes and put it aside.
Remove the cylinder head cover.
Remove the exhaust camshaft rocker arms.
Turn the crankshaft to the TDC of the piston of the first cylinder.
Remove the crankshaft pulley and damper as described in section 3.7.
Remove the chain tensioner. Remove the tensioner spring.
Mark the chain and sprockets with paint as shown in Fig. 91.
Material taken from a web resource [MercedesMAN]
Fig. 91. Applying marks to the sprocket and drive chain.
Holding the right camshaft in the middle with a wrench, unscrew the sprocket mounting bolt.
Without removing the drive chain, remove the sprocket from the right camshaft.
Remove the chain guide from the camshaft housing (section 3.10.4).
Using an impact puller, remove the tensioner shoe axle.
Remove the tensioner shoe. Check the shoe's working surface for wear and damage and replace it if necessary. Remove the shoe's coating with a screwdriver. Install a new coating in the groove and secure it.
Install the tensioner shoe in the reverse order of removal.
Coat the flange of the shoe axle with sealant and place it in the cylinder block until it stops. Align the marks on the chain and sprocket, place the sprocket on the camshaft. Holding the camshaft from turning, tighten the mounting bolt and tighten to 80 Nm.