Parts for your 2020 Subaru Impreza-Control arms

2020 Subaru Impreza Control-Arms: What They Do and When to Service Them

Control-arms are absolutely fitted to the 2020 Subaru Impreza. Technical references include the Subaru Service Manual (STIS) which details a front MacPherson strut set-up with a lower control arm, and a rear double-wishbone layout that uses control arms to locate the hub. Genuine Subaru parts catalogues (FAST/EPC) also list front lower control-arm assemblies and rear lateral/control arms for the 2020 Impreza (GK/GT series). So, they’re relevant and essential on this model.

On this Impreza, the control-arms form the backbone of the suspension geometry. Up front, the lower control-arm ties the hub to the subframe, managing wheel position through bumps and braking while the strut handles damping. Out back, the double-wishbone arrangement uses multiple arms to keep the tyre planted and stable, sharpening turn-in and keeping the ride tidy over rough roads. Bushes in the arms soak up vibration, while ball joints allow smooth steering and suspension movement without play.

There’s no set replacement interval for control-arms, they’re replaced on condition. Over time, bushes can crack or leak (where hydraulic-style bushes are used), and ball joints can develop play. For a car doing typical ANZ kilometres, it’s smart to have the arms, bushes and ball joints inspected during routine services—especially if the car sees rough roads or speed humps daily.

If replacement is needed, many owners opt for complete arm assemblies to refresh bushes and ball joints in one go. After any arm replacement, a full four-wheel alignment is a must on the Impreza’s platform to protect tyre life and keep the steering tracking straight. Where the Subaru manual specifies, use new self-locking nuts/bolts, and final-torque the arm bolts at normal ride height to avoid preloading the bushes. Quality aftermarket arms can be fine, but OE-grade components will typically deliver the best NVH and alignment stability.

• Tell-tale signs: clunks over bumps, vague steering, pulling under braking, uneven tyre wear, or a shimmy at speed.
• Service tip: inspect bushes for cracks and separation, check ball joints for axial/radial play and split boots.
• Driving harsh roads? Shorten inspection intervals, small faults caught early save tyres and alignments later.

How long do the control arm bushes last on a 2020 Subaru Impreza?

Most see well over 80,000–120,000 km, but it varies with road conditions and loads. Urban kerbs, potholes and speed humps accelerate wear.

Regular checks during scheduled services help spot early cracking or movement so the arm or bush can be replaced before it affects tyre wear or handling.

Do I need a wheel alignment after replacing control-arms?

Yes. Any change to arms, bushes or ball joints on the Impreza alters alignment. A proper four-wheel alignment restores caster, camber and toe, protecting tyres and keeping steering feel crisp.

Can worn control-arms cause uneven tyre wear and braking pull?

They can. Excess bush movement or ball joint play lets the wheel shift under load, leading to inner/outer edge wear, tramlining and a pull when braking.

If those symptoms appear, get the suspension checked promptly—often an arm and alignment fix the lot.