OVERVIEW
Genuine VW/Audi M8 × 22mm Transmission Socket Head Bolt
N-903-663-01 is an original M8 × 22mm socket head bolt listed at specified manual-transmission selector and clutch-actuation fastening points in the applications below. It provides the correct size of fastening hardware for that original location. This listing supplies one individual bolt; selector parts, clutch-actuation components and additional bolts are separate items.
Technical details
- OEM number: N-903-663-01 / N90366301.
- Factory catalog size: M8 × 22mm; 8mm nominal metric thread diameter and 22mm nominal bolt length.
- Head and drive: Socket head with an internal drive recess, as shown in the original archive photograph.
- Confirmed location: DHW internal selector position 17, or the assigned RS4 clutch-actuation position 7. Match the application-specific diagram.
- Supplied quantity: One bolt. Quantity used varies by assembly; order the quantity required by the specific repair.
- Application control: Exact original part number, transmission code and fastening position.
The diameter, length and head seating arrangement must all match the assigned joint. A bolt with the same M8 thread can still be unsuitable if its length or bearing surface differs. Incorrect hardware can bottom in the receiving hole or provide inadequate engagement instead of clamping the intended component. No unverified strength grade, material treatment or adhesive specification is claimed.
The factory parts table also lists N-903-663-03 as a separate self-locking entry at this assembly position. Confirm which revision and fastening treatment the actual transmission and current repair procedure require. This listing is for N-903-663-01 and does not establish that the earlier bolt can replace every later self-locking arrangement.
Common reasons to replace
Replace the original bolt when its internal drive is rounded, its threads are stripped or cross-threaded, corrosion compromises the seating surfaces, or the hardware is missing during gearbox service. Correct an unsuitable substitute found during a prior repair. Follow any requirement in the applicable factory procedure to renew fastening hardware after disassembly.
Inspect the receiving threads and retained component before installation. Damaged threads, a cracked component or distortion at the mounting point need separate attention. A replacement bolt cannot restore worn selector parts, damaged synchronizers or a malfunctioning clutch. Diagnose a shifting complaint before treating this fastener as the cause.
Fitment
Identify the installed transmission by its stamped code and match the original parts diagram. A gearbox replacement can change the required hardware even when the vehicle's model, engine and year remain the same. Each confirmed profile is limited to its stated transmission and fastening point.
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Audi A4 | 1998 | 1.8L turbo gasoline inline-four | B5 sedan; front-wheel drive; original DHW transmission; Five-speed manual 012 / 01W; DHW code only for this confirmed profile | Original internal selector assembly position 17 specifying N90366301, M8 × 22. Match original hardware and current factory repair requirements; the catalog separately lists self-locking N90366303. Not a universal replacement for that other revision, a quattro gearbox, or an external linkage bolt. |
| Audi RS4 | 2007–2008 | 4.2L naturally aspirated gasoline V8 | B7 sedan; quattro; six-speed manual; Factory six-speed manual | Specified clutch actuation assembly bolt at catalog position 7, PR TK7, assigned N90366301 M8 × 22mm. Confirm current original-number assignment and required fastening treatment. Do not substitute this bolt wherever N90366303 self-locking hardware is required. |
| Audi RS4 Cabriolet | 2008 | 4.2L naturally aspirated gasoline V8 | B7 convertible; quattro; six-speed manual; Factory six-speed manual | Specified clutch actuation assembly bolt at catalog position 7, PR TK7, assigned N90366301 M8 × 22mm. Confirm current original-number assignment and required fastening treatment. Do not substitute this bolt wherever N90366303 self-locking hardware is required. |
Installation and service guidance
Access to the specified selector or clutch-actuation attachment depends on the factory repair procedure and may involve removing or disassembling the transmission. Keep the work area clean, protect exposed gearbox components from debris and use the correctly fitting driver fully seated in the bolt head. Align the original components before tightening so the bolt is not used to pull a misaligned part into place.
Follow the specified tightening procedure and any required fastening treatment for the exact original revision. Use the applicable instructions for the specified DHW selector or RS4 clutch-actuation assembly; there is no universal tightening value based solely on an M8 diameter. Renew any seals or additional hardware required by that procedure and verify selector operation before completing assembly.