OVERVIEW
Factory hex-socket hardware for the specified idler pulley
N-014-733-8 is a Genuine VW/Audi M10 x 50 internal-hex bolt. In the confirmed application below, it secures the specified idler pulley in the alternator-belt drive on the 4.2L T81 engine.
The original pulley arrangement depends on the correct bolt length, head clearance and seating geometry. This individual bolt does not include the pulley, bearing, protective cap, belt or any separate mounting hardware.
Technical details
- Complete factory number: N-014-733-8.
- Factory specification: M10 x 50 mm, internal six-sided hex drive.
- Design: Cylindrical socket head and threaded shank; match the complete original factory number.
- Quantity supplied: one individual bolt.
The M10 x 50 specification gives the nominal thread diameter and fastener length. No unverified thread pitch, strength class, shipping dimensions or weight are added.
Common reasons to replace
- A rounded internal-hex recess that prevents controlled removal or tightening.
- Damaged threads, a bent shank or a damaged head seating surface.
- A missing bolt or incorrectly substituted hardware discovered during belt-drive service.
Inspect the idler bearing, pulley surface, belt and mounting bore. Belt noise or bearing play usually requires diagnosis of the pulley assembly; replacing the bolt alone does not repair a worn bearing or damaged mounting component.
Vehicle fitment
Match the engine branch and original idler-pulley location in the table. Shared 4.2L displacement does not establish compatibility with a later engine or a different pulley arrangement.
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Audi A8 L | 2004 | 4.2L V8 gasoline, PR T81 (077-series) | D3 long-wheelbase sedan, quattro; Automatic | Alternator-belt idler pulley bolt at the original N-014-733-8 location. For the T81 4.2L engine branch; not later FSI or 5.2L S8 hardware. |
Installation guidance
Relieve belt tension using the prescribed method before servicing the pulley. Keep the correct spacers and mounting pieces in their specified order and start the bolt without cross-threading.
Use a fully seated hex bit and the factory tightening specification for the exact idler joint. Verify pulley alignment, belt routing and clearance before operating the engine.
Ordering information
New and unused inventory. Sold individually as N-014-733-8. Confirm the original complete number, engine specification and required quantity before ordering.