OVERVIEW
Genuine Six-Speed Gearbox Housing Hardware
The N-903-664-01 Genuine VW/Audi Torx bolt secures the matched housing components of the original 01E six-speed manual gearbox. Its correct length, seating shape and threaded section allow it to fit the specified fastening positions without substituting a generic bolt. This listing supplies one bolt.
Technical Details
- OEM part number: N-903-664-01.
- Catalog specification: M8 × 60 × 28.
- Nominal thread diameter: M8; nominal bolt length: 60 mm.
- Drive: internal Torx; rounded head and partly threaded shank as shown in the original product photo.
- Application: matched original 01E six-speed manual gearbox housing.
- Catalog locations: housing illustration positions 24 and 36 on the referenced A6 assembly.
- Quantity supplied: one bolt; housing, seals and other fasteners are separate.
The housing assembly uses several different bolt lengths. Select the part assigned to the actual location rather than replacing every M8 fastener with this length. Correct bolt engagement and an undamaged seating surface are necessary for the joint to clamp as intended.
Common Reasons to Replace
- The Torx recess has been rounded during previous removal and no longer accepts the tool securely.
- Threads have been stripped, cross-threaded or damaged by corrosion.
- The shank or head shows visible damage after gearbox disassembly.
- The original fastener is missing or a previous repair installed a bolt of the wrong length.
- The vehicle-specific repair procedure requires renewed hardware during housing service.
Oil seepage at a housing joint requires diagnosis of the sealing surfaces, sealant and associated seals. Replacing a bolt alone does not repair a cracked housing, stripped female threads or a failed seal. Inspect those components before reassembly.
Vehicle Fitment
Fitment below applies to the original gearbox housing fastening positions, with the listed drivetrain. Confirm the transmission identification and original fastener location before ordering.
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Audi A6 | 2002–2004 | 2.7L V6 biturbo gasoline | C5/4B quattro sedan with the matched original 01E gearbox housing; Six-speed manual; quattro | Original N-903-664-01 at gearbox housing catalog positions 24 and 36, specification M8 × 60 × 28. Match the original housing and fastener location; automatic transmissions and other housing bolt lengths are excluded. |
Ordering and Installation Notes
This is the original N-903-664-01 revision. Similar-looking gearbox bolts can differ in length and seating configuration, so match the complete part number and catalog position. The catalog describes multiple pieces at these positions; this product supplies one bolt rather than a complete housing hardware set.
Use the factory repair procedure for the identified gearbox. Follow its bolt sequence, tightening specification, thread preparation and any renewal instructions. No universal torque or threadlocker requirement is assigned here because the specific joint controls installation. Support and disassemble the transmission using the prescribed workshop equipment.
The seven-image gallery repeats the available original archive photograph with distinct descriptive metadata. Repeated images show the same single part and do not indicate a multi-bolt kit.