OVERVIEW
Genuine VW/Audi ball joint lock nut, part number N-909-429-01. This self-locking nut secures the assigned ball joint connection. It is used at the catalog-specified threaded attachment point, where the correct thread and locking design are needed to retain the joint during steering and suspension movement.
Technical details
- OEM part number: N-909-429-01 / N90942901.
- Thread specification: M12 x 1.5.
- Self-locking hexagon nut; the original photo shows its head profile and threaded opening.
- Ball joint lock-nut application. The smaller retainer nuts securing the ball joint flange to the control arm can have separate part numbers.
- Supplied as one nut. Ball joint, control arm, stud and additional mounting hardware are separate.
Common reasons to replace
Replace a nut with damaged threads, a rounded hexagon, corrosion affecting its seating surface or a locking feature that no longer retains as intended. Ball joint removal or replacement is also an occasion to install the new locking hardware required by the repair procedure. An incorrect nut can engage poorly or fail to provide the intended retention even when its outside shape appears similar.
Clunking, steering play or uneven tire wear warrants diagnosis of the joint and associated suspension components. Those symptoms can come from a worn ball joint, bushing or loose connection; a new nut alone does not restore a worn joint or damaged stud.
Installation and service notes
Identify the exact attachment position in the vehicle's steering and suspension diagram before ordering. Inspect the stud, mating threads and seating surface. If the stud threads are damaged or the joint has excess play, address that defect rather than forcing a new nut onto the connection.
Follow the applicable repair procedure for supporting the suspension, separating the joint and renewing self-locking hardware. Use the prescribed method to prevent the stud from turning during tightening, and apply the vehicle-specific torque and any required additional tightening step. Do not use a generic torque based only on the thread diameter. Confirm that the joint is correctly seated and perform any alignment checks required by the repair.
Fitment
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Audi Q3 | 2018 | 2.0L turbo gasoline | Premium Plus; quattro; Transmission does not determine the assigned ball joint nut fitment | Use at the ball joint stud / lock-nut position specifying N90942901. The ball joint-to-control-arm retainer nuts are different hardware; confirm location by VIN and diagram. |
| Audi Q3 | 2018 | 2.0L turbo gasoline | Premium; quattro; Transmission does not determine the assigned ball joint nut fitment | Use at the ball joint stud / lock-nut position specifying N90942901. The ball joint-to-control-arm retainer nuts are different hardware; confirm location by VIN and diagram. |
| Audi Q3 | 2016 | 2.0L turbo gasoline | Prestige; front-wheel drive; Transmission does not determine the assigned ball joint nut fitment | Use at the ball joint stud / lock-nut position specifying N90942901. The ball joint-to-control-arm retainer nuts are different hardware; confirm location by VIN and diagram. |
| Audi Q3 | 2016 | 2.0L turbo gasoline | Prestige; quattro; Transmission does not determine the assigned ball joint nut fitment | Use at the ball joint stud / lock-nut position specifying N90942901. The ball joint-to-control-arm retainer nuts are different hardware; confirm location by VIN and diagram. |
| Volkswagen Tiguan | 2015 | 2.0L turbo gasoline | SE; first generation; front ball joint connection; Transmission does not determine the assigned ball joint nut fitment | Use at the ball joint stud / lock-nut position specifying N90942901. The ball joint-to-control-arm retainer nuts are different hardware; confirm location by VIN and diagram. |
| Volkswagen Passat | 2015 | 2.0L TDI diesel | TDI SEL Premium; front ball joint connection; Transmission does not determine the assigned ball joint nut fitment | Use at the ball joint stud / lock-nut position specifying N90942901. The ball joint-to-control-arm retainer nuts are different hardware; confirm location by VIN and diagram. |
Match the OEM part number, original joint location and vehicle equipment before ordering. The table identifies confirmed catalog configurations.