Removing Camshafts

Component overview of cylinder head/camshafts (view of bank 1-3): 

Fig 1: Camshafts/Cylinder Head Components Location

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Camshafts/cylinder head

Individual parts of camshafts: 

Fig 2: Camshafts/Camshaft Controllers Components Location

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Camshafts/camshaft controllers

Information 

• The camshafts can only be removed in the overlapping position at the top dead Centre of pistons 1 or 4. 
• Only at this position can you be sure that the valves are not touching against the pistons and cannot be damaged when the engine turns. 

1. Turn the engine at the assembly support so that the cylinder bank to be worked on is at the top.
2. Use > 9773 - turning device to turn the crankshaft at the vibration damper clockwise  as far as the TDC marking of cylinder 1/4 

   The marking shows the letter A and the code OT1. 

   Fix the vibration damper in place above the staking bore using > 9595/1 - locating pin-1 -  .

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   TDC position of vibration damper

3. Check cam position on cylinder 1 or cylinder 4.

   Overlap of cylinder 1 (viewed from above):  The cams must be facing downwards at an angle to the cylinder head wall -Arrows-  .

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   Cam position of cylinder 1 at overlapping TDC

   1	Intake camshaft
   2	Outlet camshaft

   Overlap of cylinder 4 (viewed from above):  The cams are facing each other and are at a slight angle with respect to the sparkplug bore -Arrows-  .

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   Cam position of cylinder 4 at overlapping TDC

   1	Intake camshaft
   2	Outlet camshaft

4. Other marking:  Check position of data matrix code on both camshafts.

   These must be facing the observer at overlapping position! 

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   Data matrix code on the camshafts

   1	Data matrix code on intake camshaft (at overlapping position)
   2	Data matrix code on outlet camshaft (at overlapping position)

   Overview of central screws for camshaft controllers:

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   Installation overview of central screws for camshaft controllers

   1	Camshaft controller, intake
   2	Camshaft controller, outlet
   3	Central screws (central valves)

5. Loosen central screws.

   Tools: 

   • -item 1-: > 9863/3 - Open-ended wrench, a/f 39 for counterina 
   • -item 2-: > 9863 - Socket wrench for camshaft 
   • -item 3-: > V.A.G 1332 - Torque wrench. 40-200 Nm (30-148 ftlb.) 

   Counter at the hexagon drivers -arrow-  with an open-ended wrench.

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   Central screw for camshaft controller (view of intake side)

   Information 

   • The chain tensioner from the 1 st generation 991 engine is used for setting the timing on the 992 engine. 
   • This has a higher spring force and allows more accurate adjustment. 
6. Remove chain tensioner.

   Use chain tensioner 9A1.105.157.02 (1st generation 991 engine) for setting the camshaft timing. 

   Cylinder bank 1-3:  Chain tensioner is on the outlet side.

   Cylinder bank 4-6:  Chain tensioner is on top of cylinder head.

   Replace sealing rings

7. Remove camshaft controllers -1-  .

   Unscrew central screws with drivers on the camshaft controllers -1-  .

   Lift the timing chain and remove camshaft controllers -1-  one by one.

   Replace friction plates -2-  !

   Put camshaft controllers -1-  back on the camshafts for storage and tighten central screws by hand.

   Replace hexagon drivers. 

   Lay the timing chain in the chain housing in the cylinder head.

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   Friction plate in camshaft controller

   1	Camshaft controller (back)
   2	Friction plate

8. Remove camshafts.

   Loosen and unscrew screws on bearing saddle -13 to 16-  .

   Loosen and unscrew screws on bearing covers -1 to 12-  from the outside in.

   Remove bearing saddle and bearing covers.

   Fig 3: Camshaft Bearing Cover Screws Tightening Sequence

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   Tightening sequence for camshaft bearing cover

   Information 

   • Do not clean the camshaft controller in a parts washer. 
   • Only the outside can be cleaned using a clean, lint-free cloth. 
9. Clean the components.