OVERVIEW
Fine-thread hardware for the specified rear differential
N-903-614-01 is the Genuine VW/Audi hexagon bolt used inside the rear differential assembly identified below. Its M10 x 1 fine thread and 22.8 mm nominal length are part of the original fastening specification.
Internal final-drive work requires precise hardware selection and assembly. The same vehicle can use different final-drive units, so the code on the installed differential is essential when identifying the correct bolt.
Technical details
- Complete factory number: N-903-614-01.
- Factory specification: M10 x 1 x 22.8 mm.
- Design: hexagon-head differential fastener.
- Quantity supplied: one individual bolt.
The 1 mm pitch distinguishes this bolt from common coarse-thread M10 hardware. The factory diagram lists ten bolts at this internal fastening position; this listing supplies one bolt and does not constitute a complete repair set.
Common reasons to replace
- The factory differential repair procedure requires replacement hardware.
- The threads are damaged or have been cross-threaded.
- The head or bearing surface is damaged during removal.
- Corrosion or prior incorrect hardware makes reliable assembly uncertain.
Inspect the mating threads and differential components before assembly. A replacement bolt cannot correct damaged gears, a distorted carrier or an incorrectly set final drive.
Vehicle fitment
Fitment is conditional on the installed rear differential code. Confirm the code and the original internal bolt position in addition to the vehicle model.
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Audi A4 | 2001 | 1.8L turbocharged I4; 2.8L gasoline V6 | B5 sedan and Avant; quattro; Rear differential CKK, DAJ, DAK, DQA or DRL only | Original internal differential fastening position; verify rear final-drive code before ordering. |
| Audi S4 | 2001 | 2.7L twin-turbocharged gasoline V6 | B5 sedan and Avant; quattro; Rear differential CKK, DAJ, DAK, DQA or DRL only | Original internal differential fastening position; verify rear final-drive code before ordering. |
Installation guidance
Have internal differential repairs performed using the factory final-drive procedure. Follow the specified replacement policy, thread preparation, tightening sequence and torque or angle requirements for the exact unit.
Complete all required bearing, gear-contact and final-drive adjustment checks before returning the assembly to service. Verify sealing and lubricant requirements independently of the fastening hardware.
Ordering information
Sold individually as one genuine bolt. Gears, bearings, seals, lubricant and other hardware are separate. Confirm the rear final-drive code and repair quantity before ordering.