Engine M110
1. Using a soft metal drift, press the rear bearing shaft flush into the cylinder block. Make sure the groove is in the uppermost position.
2. Install the front bearing onto the intermediate shaft, then, after lubricating the rear bearing, insert both bearings into the cylinder block. Make sure the woodruff key is in the groove of the shaft.
3. Place the lock washer together with the bolt and snap ring and tighten the bolt.
4. Install the intermediate sprocket onto the shaft and remove the shaft using the bolt. Make sure the chain engages with the sprocket teeth.
5. Insert the oil supply channel bolt and washer, tighten them to the specified torque, locking the intermediate gear.
6. Insert the chain stop bolt into the cylinder block and tighten it.
7. Connect the driver to the intermediate gear, then install the distributor housing with a new gasket and align the groove of the drive gear with the driver. Insert and tighten the bolts.
8. If provided by the design, insert the oil pressure relief valve into the TDC sensor bracket. Lubricate the plug threads with sealing paste, insert and tighten the plug.
9. Install the vibration damper and pulley, insert and tighten the bolts.
10. Using the bolt, engage the oil pump drive shaft with the pump.
11. Lightly lubricate the plug with sealing paste and press it into the cylinder block above the oil pump drive shaft.
Engine M123
1. Lubricate the intermediate shaft front bearing and place it on the intermediate shaft, then insert them into the block, aligning the bearing groove with the bolt hole. Make sure the woodruff key is in the shaft groove.
Material based on data from the portal mercedesman
2. Place the locking washer and tighten the bolt.
3. Install the intermediate gear on the shaft and remove the shaft using the removal bolt. Make sure that the chain is engaged with the teeth of the sprocket.
4. Insert and tighten the bolt to lock the intermediate sprocket.
5. Insert the timing chain stop bolt into the cylinder block and tighten it.
6. Insert the right chain guide and center the pin hole. Apply a small amount of sealing paste to the pin flange and hammer it into the cylinder block.
7. Install the vibration damper and pulley, insert and tighten the bolts.
8. Engage the camshaft sprocket with the chain and place it on the camshaft. Insert and tighten the bolt, locking the sprocket with a metal rod inserted into one of its holes.
9. Place the cover on the front of the cylinder block together with the new gasket, insert the bolts and tighten them evenly.
10. Where required by the design, install a hydraulic pump for the rear suspension height control system.
11. After making sure that the piston of the 1st cylinder is still at TDC, insert the distributor shaft in place so that its groove is approximately parallel with the cylinder block and the wide segment is directed towards the engine. After installing the chain tensioner, this parallelism must be checked again.
12. Install the guide housing and distributor spacer, then insert and tighten the bolt.
For all models
If the engine is installed on the vehicle, perform all preliminary operations in reverse order.