The wheels on your car are held on by a combination of critical components that work together: the wheel studs, lug nuts, the wheel hub, and the wheel bearings. The most direct answer is the lug nuts (or bolts), which are the fasteners you see on the wheel itself. They screw onto the wheel studs—the threaded posts protruding from the hub—to clamp the wheel securely against the hub assembly. This entire assembly rotates on the wheel bearings, which are precision components allowing smooth rotation while supporting the vehicle's weight.
It's a high-stakes system. The clamping force generated when you torque the lug nuts is immense, creating enough friction between the wheel and the hub to handle acceleration, braking, and cornering forces. The hub is the central connection point, often bolted directly to the suspension and, on driven wheels, connected to the axle that delivers power from the transmission.
Proper maintenance is non-negotiable. Lug nuts must be tightened to the manufacturer's specified torque using a torque wrench. Overtightening can stretch the studs and lead to failure, while undertightening allows the wheel to loosen. A periodic inspection for rust, damage, or unusual play is a simple but crucial safety habit.
| Component | Primary Function | Key Consideration |
|---|
| Lug Nuts | Fastens the wheel to the hub | Must be torqued to spec (e.g., 80-100 ft-lbs is common) |
| Wheel Studs | Threaded posts for lug nuts | Can shear if over-torqued or impacted |
| Wheel Hub | Mounting point for the wheel and brake rotor | Houses the wheel bearing |
| Wheel Bearings | Allow the wheel to spin smoothly with minimal friction | Wear out over time, causing noise and play |
| Axle | Transmits power to the wheel (on driven wheels) | A solid connection to the transmission |
