1001IN IMPORTANT component changes for V8 engines as of October 2008

WM 1001IN IMPORTANT component changes for V8 engines as of October 2008

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Technical values

Information

Component changes for engines produced as of model year 2009, calendar week 42/2008

Information

Component changes implemented as of the following engine numbers:

- M4801 905541

- M4801G 904965

- M4851 901689

- M4851S 900562

- M4851T 901788

Information

- At present, aluminium screws are used for the cylinder head cover, timing-case cover, lower part of crankcase and oil guide housing. Observe modified tightening specifications as instructed.

- In addition, the new timing-case cover can only be retrofitted (on older engines) in conjunction with aluminium screws and the new chain tensioner.

- The joint flange behind the vibration balancer is secured to the timing-case cover with aluminium screws.

- In addition, the crankcase can only be retrofitted (in older engines) with a new starter and modified primary catalytic converter support.

- New sealant in conjunction with aluminium screws for the crankcase and oil guide housing. Old sealant must not be used if sealant is likely to come into direct contact with aluminium screws.

- The crankshaft mount now has four conventional bearings (one more colour classification). Install new crankshaft only with new modified bearing shells.

- Lower part of crankcase (outer cross bolt connection) with aluminium screws and new sealant.

- Oil guide housing with aluminium screws and new sealant.

- Cylinder heads with new spark plugs. If a cylinder head is replaced on an older engine, the spark plugs on the opposite cylinder head must be changed (replaced).

- Modified camshafts only in conjunction with modified screws for sprockets and camshaft controllers. Install new camshafts only with modified screws (external Torx) for the camshaft controller and sprocket (screw length .). The tightening torque remains the same.

- Modified ignition rod modules with aluminium screws and engine wire harness.

- Modified valve cover with aluminium screws and modified cap on solenoid valves for camshaft controllers. Eyelets still have steel screws.

- Modified valve cover and cylinder head on cylinder bank 1 to 4 have an additional M8 thread bore and M8 screw (aluminium). If the cylinder head is replaced (on older engines), the valve cover must also be replaced. Modified valve cover must be installed on the old cylinder head using an M6 screw when retrofitting the valve cover on older engines.

- Countersunk screws for securing auxiliary unit brackets and engine carrier to the crankcase. The tightening torque remains unchanged.

- Crash support (support bracket) on generator with aluminium screws.

- Always check component pairings in the Porsche Parts Catalogue.

- Always check specific engine numbers in the Porsche Parts Catalogue.

Information on aluminium screws

Information

Aluminium screws and steel screws have different properties.

- Most aluminium screws are identified on Porsche V-engines by an internal Torx screw with internal pin ( => Aluminium screw on V-engines ). Aluminium screws can be identified differently on transmissions, on the chassis and on engines from other manufacturers. The design-related distinguishing features can be omitted if necessary.

- One differentiating feature is that aluminium screws are lighter than steel screws of the same size (e.g. screws used in bar ignition modules).

- Aluminium screws are different from steel screws in that they are not magnetic. If in doubt, check the screws using a magnet.

- The aluminium screws used at present have the additional marking RIBE (manufacturer) and AL9 (strength) on the screw head. => Aluminium screw on V-engines

- Screws with an internal pin can be loosened and tightened using commercially available bit inserts with a hole (safety bits).

Aluminium screw on V-engines

- Aluminium screws must be used only once. Replace the screws whenever they have been loosened.

- Aluminium screws must always be tightened in two steps (torque and torque angle ) or require a special yield-point wrench Electronic torque wrench 9768. The specified tightening torques and torque angles must always be observed. The extent to which a screw is tightened can be limited using a yield-point wrench.

- There is no need to tighten by clicking once as this may cause irreparable damage to the screw.

- Sealants that can come into contact with aluminium screws in threaded bores must be approved for use with aluminium screws by Porsche => if this is not observed, there will be increased friction in the screw thread and the aluminium screw will break.

- Aluminium screws must not be fitted using tightening parameters for steel screws => the aluminium screw will break.

- Screw threads must be perfectly clean. Sealant residue or chips increase the friction coefficient => the aluminium screw will break. Blow out thread holes.

Aluminium screws

Overview of repair-relevant component changes as of model year 2009, calendar week 42/2008

Information

- The eyelets must not be inadvertently secured using aluminium screws. => Aluminium screws would break and the suspended engine would fall down.