Valve mechanism 1. Shaft sealing ring; 2. Bolt; 3. Nut; 4. Support frame, with integrated camshaft bearings; 5. Exhaust camshaft; 6. Intake camshaft; 7. Rocker arm, mark the mounting position for reinstallation. Check the roller bearing for ease of movement, lubricate the working surfaces before installation; 8. Hydraulic compensator, with locking bracket, mark the mounting position for reinstallation, lubricate the working surfaces before installation; 9. Valve, not subject to machining, only lapping is allowed, mark the mounting position for reinstallation; 10. Cylinder head; 11. Oil seal; 12. Valve spring; 13. Valve spring plate; 14. Valve cracker; 15. Cover, replace, removal: with the camshaft frame removed, pierce the cover with an awl on 1 side and remove it, installation: press in with a suitable mandrel without sealant, pressing depth 1-2 mm
Support frame - bolt tightening sequence and torque
Tighten the bearing frame bolts and nuts in the sequence "1...24" in 2 steps, as follows:
- 1. Screw in evenly by hand until it stops. The frame should fit against the cylinder head over the entire contact surface.
- 2. Tighten to 10 Nm.
Removal camshafts
Remove the engine casing "arrows". Remove the noise-insulating injector lining. Remove the injectors. Remove the fuel rail. Remove the toothed belt of the camshaft and high-pressure pump. Remove the valve cover. Unscrew the mounting bolts "1" of the camshaft gear. Remove the camshaft from the hub.
Hold the hub with the counter support "T10051" and loosen the hub mounting bolt "1". Unscrew the hub mounting bolt by about 2 turns.
Install the puller "T10052" and align it with the holes in the hub. Tighten the mounting bolts -1. Increase the tension of the hub by uniformly tightening the puller "2" until the hub is disconnected from the camshaft cone. Fix the puller with a 30 spanner. Remove the hub from the camshaft cone. Remove the vacuum pump.
Remove vacuum hose "1".
Unscrew bolts "2" and "4". Do not unscrew lines "1" and "2". Unscrew bolts arrows - and tie up the EGR cooler.
Unscrew the "arrow" bolts and remove the EGR system bracket.
Loosen the frame mounting bolts in the sequence "24...1". Remove the camshaft frame. Mark for reinstallation and remove the camshafts.
Install
Apply silicone adhesive sealant to the mating surfaces between the crankshaft frame and the cylinder head. The camshafts should only be installed using the "T40094" camshaft stand as described below. Remove any remaining sealant from the cylinder head and camshaft frame, e.g. with a rotating brush attachment with plastic bristles. Cover the exposed parts of the engine. Remove any remaining sealant from the cylinder head and crankshaft frame, e.g. with a rotating brush attachment with plastic bristles. Clean the mating surfaces; there should be no oil or grease on them. Lubricate the working surface of the camshafts with oil. Equip the camshaft installation tool "T40094" as follows: Screw the supports "T40094/9" and "T40094/10" (with "T40094/11") onto the main plate, as shown in the figure. If necessary, unscrew the screwed supports at this point.
Install support "T40094/1" to position "F" and support "T40094/2" to position "A".
Place the intake camshaft on supports "T40094/1" and "T40094/2". Turn the intake camshaft so that it can be locked with the lock in the "TDC" position "arrow 1". The concavity "arrow 2" of the cylinder head bolt must be facing outward.
Place the exhaust camshaft on the supports "T40094/9" and "T40094/11". Secure the exhaust camshaft with the cover "T40094/11". Protrusion "1" of the cover must enter groove "2" in the camshaft. Install the clamping tool "T40096/1" on the gear engagement of the exhaust camshaft so that each journal of the clamping device engages on each half of the gear. The wide journal must enter the wide half of the gear. Tighten the clamping device with a knurled wheel until the tooth profiles are flush. Push the intake camshaft toward the exhaust camshaft so that their teeth engage "arrows".
Install the frame onto the camshafts. All camshaft bearings must be on the camshafts. Install the camshaft stand "T40095" and secure the camshafts in the frame as shown in the figure. Remove the cover "T40094/11".
Cut off the tube tip along the front mark (hole about 2mm). Apply beads of sealant (width approx. 2...3 mm) "arrows" on the clean cylinder head mounting surfaces, as shown in the figure. The sealant beads must not be thicker than specified, since otherwise excess sealant may get into the camshaft bearings. Remove the camshafts together with the frame, the "T40095" camshaft stand and the "T40096/1" clamping tool from the "T40094" camshaft stand and carefully insert them into the cylinder head.
Tighten the frame mounting bolts in the sequence "1...24", first by hand. The frame must fit against the cylinder head over the entire contact surface. Tighten the frame bolts further in the sequence "1...24". Remove the camshaft installation tool "T40095" and the clamping device "T40096/1". Installation is in the reverse order, while paying attention to the following: Replace the camshaft seal. Press the new sealing cover onto the cylinder head using a suitable drift until it is flush. Install the vacuum pump. Install the cylinder head cover. Risk of damage to the valves and piston crowns after working on the valve mechanism. Since the hydraulic valve lifters must be settled, do not start the engine for about 30 minutes after installing the camshafts. To ensure that no valve comes into contact with the cylinder head during operation, carefully turn the crankshaft at least 2 revolutions.