Parts for your 2021 Subaru Impreza-Control arms

2021 Subaru Impreza control arms: what they do and when to replace them

Yes — the 2021 Subaru Impreza uses control arms. Technical references including the Subaru Factory Service Manual (Suspension section for the 2019–2022 Impreza), Subaru’s Global Platform technical overview, and the OEM parts catalogue (listing the front “arm complete – lower/transverse link” and rear lateral/trailling control arms) all confirm front MacPherson struts with a lower control arm, and a rear double-wishbone layout with multiple control arms.

On this Impreza, the control arms are the sturdy links that locate the wheels and let the suspension move in a controlled arc. Up front, the lower arm ties the hub to the subframe via bushes and a ball joint, managing camber and caster as the strut does the springing and damping. Down the back, the double-wishbone arrangement uses a mix of lateral and trailing control arms to keep the wheel planted and the ride comfy over rough Kiwi and Aussie roads.

Why they matter? Healthy control arm bushes and ball joints keep steering sharp, braking stable, and tyres wearing evenly. As bushes age, they can crack or go soft, ball joints can develop play. That leads to clunks over bumps, vague steering, pulling under brakes, or inside-edge tyre wear.

Good servicing habits for a 2021 Impreza include a visual check of the front lower control arm bushes and ball joints every service or 10,000–15,000 km, and the rear arm bushes for splits or leaking hydro-bushes. If any arm or bush is worn, it’s best practice to replace in pairs (left and right), then get a full wheel alignment. Torque all fasteners at ride height (with the vehicle’s weight on the wheels) to avoid preloading new bushes. Always follow the Subaru workshop manual for torque specs and any one-time-use fasteners.

Owners often ask whether to choose genuine or aftermarket. Quality aftermarket arms and bush kits can be great value, but stick to reputable brands that match OEM geometry and bushing durometer. During replacement, also inspect sway bar links, inner/outer tie rods, and strut mounts, tackling these together can save time and a second alignment. If the car sees rough roads or heavy loads, consider more frequent inspections. And if there’s a sudden knock, steering wander, or odd tyre wear, book it in sooner rather than later — a tired control arm can snowball into bigger costs and safety risks.

• Common signs to replace: clunking over bumps, wandering steering, uneven tyre wear, vibration under braking.
• After replacement: perform alignment, recheck fastener torque after a few hundred kilometres.

Popular questions about 2021 Subaru Impreza control arms

Does the 2021 Impreza have control arms front and rear?
It does. The front uses a MacPherson strut with a lower control arm (transverse link). The rear is a double-wishbone setup that uses multiple control arms to manage wheel position. This layout is documented in Subaru’s service manual and parts catalogue for the model years covering 2021.

How long do control arm bushes typically last?
On a well-maintained 2021 Impreza driven on mixed urban and highway roads, bushes commonly last 80,000–150,000 km. Harsh roads, frequent kerb strikes, or aggressive driving can shorten that. Regular inspections during servicing will catch early cracking, fluid seep from hydro-bushes, or excess movement before it affects tyres and alignment.

Do you need a wheel alignment after replacing control arms?
Yes. Changing any control arm, bush, or ball joint alters suspension geometry. A professional four-wheel alignment resets camber, caster, and toe to spec, protecting tyres and restoring straight-line stability and steering feel.