Parts for your 2009 Subaru Impreza-Wheel studs nuts

2009 Subaru Impreza wheel studs & nuts: what they do and how to look after them

Based on technical sources — the 2009 Subaru Impreza Factory Service Manual (GE/GH), the owner’s manual, and Subaru’s electronic parts catalogue — this model uses press-in wheel studs with corresponding lug nuts (not wheel bolts). The manuals specify a wheel nut tightening torque of 120 N·m (88.5 ft‑lb) and call up M12 x 1.25 thread nuts with a 60° tapered seat. So yes, wheel studs and nuts are absolutely relevant to the 2009 Impreza.

On a 2009 Impreza, the studs are pressed into the hub and the nuts clamp the wheel and brake rotor hat firmly to the hub face. That clamp load is what keeps the wheel located and safe under braking, cornering and bumps. Because studs stay in the hub, it’s easier to hang the wheel and get the nuts started by hand — handy on the side of the road when changing a tyre.

For servicing, the big ticket is correct torque. Tighten the nuts in a star pattern to 120 N·m using a torque wrench, not just a rattle gun. If an impact driver is used to spin nuts on, always finish with a torque wrench. Avoid lubricants or anti‑seize on the threads or seats unless a Subaru bulletin says otherwise, most specs assume clean, dry threads. After wheel or tyre work, re‑torque after 50–100 km as the stack settles.

Routine checks are simple:

• Inspect nuts for rounded flats, damaged tapers, or swollen caps. Replace any suspect ones.
• Check studs for cross‑threading, corrosion, stretching (threads look pulled/thinned), or if a stud spins in the hub — that’s a sign the knurl no longer bites.
• Clean the hub face and wheel mating surfaces, rust or debris can fake torque readings and cause loosening.

If a stud breaks or threads are shot, it’s a straightforward press‑out/press‑in job once the caliper and rotor are off. Match the replacement’s knurl diameter and length to the hub, seat it squarely, and draw it in fully before fitting the wheel. Don’t “pull” a stud into place solely with a nut under heavy load — it can gall the threads, use proper support or a press where possible.

Drivers who tow, carry heavy loads, or head to track days might consider high‑quality or extended studs with matching nuts, but always keep the OEM thread pitch (M12 x 1.25) and 60° taper. Whatever the setup, correct torque and clean interfaces are what keep the wheel on straight and true.

Popular questions about 2009 Subaru Impreza wheel studs & nuts

What’s the correct wheel nut torque for a 2009 Subaru Impreza?
Subaru’s service data for the 2009 Impreza specifies 120 N·m (88.5 ft‑lb). Tighten in a star pattern and re‑check after 50–100 km of driving. Variants and aftermarket wheels can change requirements slightly, so confirm against the service manual and any wheel maker notes.

What thread size and seat type are the wheel nuts?
They’re M12 x 1.25 thread with a 60‑degree tapered (conical) seat. Always match the seat type to the wheel, don’t mix ball‑seat or mag‑seat nuts on a tapered wheel. Using the wrong seat can lead to loosening or damaged wheel seats.

How do you know a stud needs replacing?
Signs include flattened or torn threads, a stud that spins in the hub when you try to loosen/tighten the nut, obvious bending or a clean break, or nuts that won’t hold torque. If one breaks, replace it, if multiple are damaged on one hub, stop driving and sort it before the wheel loses clamp load.