To remove the camshaft, do the following:
Remove the cylinder head cover, having first disconnected the fuel lines on the left cover.
To rotate the crankshaft, place a size 27 socket wrench on the head of the central pulley mounting bolt.
Turn the crankshaft until the first cam nose is vertically upward. Press the valve with a puller and remove the rocker arm. Remove the remaining rocker arms in sequence. When reusing, mark the camshafts and rocker arms.
Turn the crankshaft and set the key in the camshaft to the upper position. Rotate the camshafts only by turning the crankshaft.
Using a screwdriver, remove the oil pipes. The pipe attachment points are shown by arrows in Fig. 50.
Fig. 50. Removing the oil pipe. The arrows show the attachment points.
Mark the sprocket and drive chain with paint as shown in Fig. 51.
In vehicles with adjustable suspension, remove the suspension hydraulic system pump and set it aside along with the pipes. Remove the pump drive components.
Holding the camshaft with a wrench in the middle to prevent it from turning, unscrew the sprocket mounting bolt and remove the sprocket.
Fig. 51. Applying marks to the drive chain and sprocket.
Loosen the camshaft bearing support mounting bolts one by one. The rear cylinder head mounting bolt can only be removed by lifting the camshaft support (see fig. 19).
Lift the camshaft together with the supports and remove the shaft from the rear support.
(Material created based on the website MERCEDESMAN)
When reusing the camshaft, perform the above checks. In addition, check the bearing supports and, if necessary, grind the shaft journals.
When installing the camshaft, do the following:
Lubricate the bearing journals, install the bearing supports and install the camshaft assembly on the cylinder head. Before installing the supports, install the cylinder head mounting bolt as shown in Fig. 19.
Lubricate the threads and bearing surfaces in the cylinder head and install the bolts.
Tighten the mounting bolts preliminarily to 30 Nm and finally to 60 Nm. Tighten the M8 bolts to 50 Nm.
Check the freedom of rotation by turning the camshaft.
Before installing the oil pipe, check the patency of all holes, replace the pipe if necessary. Install the pipe using a hammer with a plastic striker. Put on the spacer ring, aligning the groove with the key.
Place the drive chain on the sprocket, aligning the marks, and install the sprocket on the camshaft with the wide protrusion towards the shaft.
Tighten the bolt with the washer and tighten to a torque of 100 Nm, securing the shaft from turning.
Install the rocker arms as indicated.
Perform the remaining work in reverse order.