158419 Removing and Installing Camshaft Controller on 4.8-Litre DFI Engines
WM 158419 Removing and installing camshaft controller on 4.8-litre DFI engines
Preliminary work
1. Remove cylinder head cover (valve cover) on both cylinder banks. => 158219 Removing and installing cylinder head cover (valve cover) on 4.8-litre DFI engines - section on "Removing"
2. The spark plugs should be removed to make the crankshaft easier to turn. => 287020 Removing and installing spark plugs on DFI engines - section on "Removing"
Removing camshaft controller
Removing camshaft controller up to October 2008
NOTICE
Incorrect handling of crankshafts
- Risk of damage to the timing system
-> Never turn the crankshaft against the rolling direction or when the chain tensioner is removed.
-> Proceed carefully with your work.
-> Only turn the engine at the crankshaft.
-> Reset the timing after working on the camshaft.
-> Observe general warning notes and working regulations.
NOTICE
Small parts falling into the timing case
- Risk of engine damage
-> Do not let the diamond washer and other small parts fall into the timing case.
Information
- The diamond washers on the camshaft controllers must be replaced following the complete removal of the camshaft controllers. If the fastening screw for the camshaft controller is only loosened in order to set the timing (1 or 2 revolutions), the diamond washer does not need to be replaced.
1. Turn the crankshaft at the vibration balancer so that the vibration balancer's staking bore -2- is located approx. 45° ° in front of the lower staking point on the timing-case cover -1-.
Staking bore 45 ° before TDC of cylinder 1
2. Remove chain tensioner. => 153619 Removing and installing chain tensioner on 4.8-litre DFI engines - section on "Removing".
3. Loosen all four screws on the camshafts (sprockets and camshaft controllers) by one to two turns. Counter at the respective hexagon.
Loosening camshafts (shown with timing-case cover removed)
Information
- Move the camshafts carefully. Do not force.
- Turn in the other direction if necessary.
Information
A data matrix coding is shown on the staking dihedron of the camshafts. This is a square black/white dotted marking used for electronic identification purposes during the production process. This marking can be used as an aid when inserting the camshafts into the cylinder head. All four camshafts press against the valves the least when the data matrix coding is facing upwards during installation.
4. Turn all four camshafts so that all the data matrix codings at the adjustment edges are pointing upwards almost simultaneously (this enables the camshafts to exert the minimum amount of pressure on the valve lifters) => Camshaft position for cylinders 1 to 4 => Camshaft position for cylinders 5 to 8. The camshafts are turned at their hexagon using an appropriate open-ended wrench => Hexagon at camshaft. Observe identical information on assembling the camshafts.
Camshaft position for cylinders 1 to 4
Camshaft position for cylinders 5 to 8
Hexagon at camshaft
5. Loosen timing chain.
6. Remove screw for the respective camshaft controller -1- and carefully take out camshaft controller -3- with both hands under the timing chain => Removing camshaft controller from chain. Carefully loosen the camshaft controller from behind using a rubber hammer if necessary => Loosening camshaft controller. Replace the diamond friction washer when removing the camshaft controller.
Camshaft control
Hexagon sleeve and camshaft controller screw
Loosening camshaft controller
Removing camshaft controller from chain
Installing camshaft controller
Installing camshaft controller up to October 2008
NOTICE
Incorrect handling of crankshafts
- Risk of damage to the timing system
-> Never turn the crankshaft against the rolling direction or when the chain tensioner is removed.
-> Proceed carefully with your work.
-> Only turn the engine at the crankshaft.
-> Reset the timing after working on the camshaft.
-> Observe general warning notes and working regulations.
NOTICE
Small parts falling into the timing case
- Risk of engine damage
-> Do not let the diamond washer and other small parts fall into the timing case.
Camshaft control
1. Replace the diamond washer under the camshaft controller. => Replacing diamond washer
Replacing diamond washer
2. Lift timing chain and place camshaft controller carefully on the camshaft => Camshaft controller on camshaft. In order to have sufficient play in the timing chain, turn camshaft timing gear back and forth as required => Turning camshaft timing gear. Place timing chain on camshaft controller.
Camshaft controller on camshaft
Turning camshaft timing gear
3. Position fastening screw and hexagon on the camshaft controller and screw in loosely (it must still be possible to turn the camshaft controller) => Positioning fastening screws on the camshaft controller.
Positioning fastening screws on the camshaft controller
4. Screw in the four screws on the sprockets and camshaft controller as far as possible (it must still be possible to turn the sprockets and camshaft controller to set the timing).
5. Set the timing. => 150516 Setting camshaft timing on 4.8-litre DFI engines. Do not tighten the sprockets and camshaft controller to the final tightening torque until the timing has been set.
Subsequent work
1. Fit spark plugs. => 287020 Removing and installing spark plugs on DFI engines - section on "Installing"
2. Fit valve cover. => 158219 Removing and installing cylinder head cover (valve cover) on 4.8-litre DFI engines - section on "Installing"