N-911-439-01 Genuine VW/Audi Crankshaft Vibration Damper Bolt - M8 x 16

Genuine VW/Audi crankshaft vibration damper bolt, part number N-911-439-01. This original fastener retains the crankshaft pulley/vibration damper at its assigned peripheral mounting position. One bolt is supplied; the confirmed Golf R arrangement uses six.

Technical details

• Original number: N-911-439-01 / N91143901.
• Published nominal size: M8 x 16.
• Socket head with internal multipoint drive, as pictured.
• Application: crankshaft vibration damper retaining hardware.
• Quantity supplied: one bolt. Damper and remaining hardware are separate.

The vibration damper is retained by multiple fasteners around the center crankshaft connection. This bolt belongs to that retaining pattern. It is separate from the large center crankshaft bolt and must not be used as a substitute for that fastener.

The exact length, head and mounting position matter for correct damper seating. Other pulley or timing-related fasteners may look similar while requiring different hardware. Match the original number and engine arrangement before ordering.

Common reasons to replace

Renew the damper retaining bolts when required by the factory procedure during pulley removal or related timing-belt access. The published Golf R repair procedure calls for new vibration damper mounting bolts during reassembly.

Replace any missing fastener or one with stripped threads, a rounded internal drive, corrosion or deformation that prevents controlled installation. Prior repairs can leave mismatched hardware in the six-bolt pattern; inspect every position rather than replacing only the most visibly damaged bolt.

Pulley movement, abnormal vibration or noise requires diagnosis of the damper and its complete connection. A new bolt cannot repair a damaged damper, incorrectly seated pulley, damaged crankshaft components or stripped mating threads. Correct the diagnosed cause before reassembly.

Installation and service notes

Use the factory procedure for the exact engine and crankshaft pulley arrangement. Damper removal can be part of timing-belt service, so observe the required engine positioning and timing checks before disturbing the assembly.

Identify the peripheral retaining bolts separately from the center crankshaft bolt. The factory procedure specifies holding the center connection while removing the damper retaining hardware. Use the prescribed holding method and tools; do not improvise by loading unrelated engine components.

Inspect the mounting surfaces, bolt holes and damper before fitting it. Seat the assembly correctly and start the assigned bolts by hand in undamaged threads. Do not use a bolt to pull a misaligned damper into place or overcome resistance from an incorrectly located component.

Engage the correct multipoint tool fully in the socket and follow the specified tightening sequence. Observe the engine-specific thread preparation, tightening and renewal requirements. A generic M8 specification does not replace the repair procedure for this attachment.

Check that the complete retaining pattern has the correct hardware and that all disturbed timing covers, brackets and belt-drive components are restored as prescribed. Complete the required timing and operating checks before returning the vehicle to service.

Fitment

Confirm N91143901 at the crankshaft vibration damper retaining pattern. Order the required quantity separately; one bolt supplied.