Parts for your 2018 Subaru Impreza-Control arms

2018 Subaru Impreza Control Arms

Control arms are absolutely used on the 2018 Subaru Impreza. The Subaru Service Manual for the 2017–2019 Impreza (Suspension – Front Suspension) specifies a MacPherson strut front end with a lower control arm on each side, and Subaru’s electronic parts catalogue (FAST/EPC) lists “Front arm assembly – lower, LH/RH” for this model. At the rear, the Impreza runs a multi-link/double-wishbone layout with lateral links and trailing arms that many catalogues also refer to as rear control arms. So yes—control arms are relevant on this vehicle.

On a 2018 Impreza, the front lower control arms locate the hub and wheel fore/aft and laterally, setting the geometry that keeps the car stable, predictable, and kind to its tyres. They pivot on rubber bushes at the subframe and connect to the steering knuckle via a ball joint, allowing the wheel to move up and down while staying properly guided. According to Subaru’s workshop documentation, any looseness at the bushes or ball joint can throw out alignment and upset braking feel and steering accuracy.

For everyday servicing in Australia and New Zealand, it’s smart to have the control arm bushes and ball joints inspected at each service interval, especially if the car sees gravel roads, kerb knocks, or plenty of city speed humps. Typical signs it’s time to act include:

• Clunks over bumps, shimmy under braking, or a steering wheel that won’t stay straight
• Uneven or rapid inner/outer tyre wear
• Visible bush cracking, torn dust boots, or play in the ball joint

When replacement’s due, many owners choose complete arm assemblies with bushes and ball joint pre-fitted—it saves press work and often the labour costs balance out. Quality aftermarket or genuine arms both do the job, just avoid no-name units with vague specs. If only the bushes are worn and the arm is sound, pressing new bushes can be cost-effective, provided the correct tools and procedures are used.

Key workshop tips echoed in Subaru service literature: torque the pivot bolts at normal ride height (not with the suspension hanging), replace any single-use hardware as specified, and always book a full four-wheel alignment afterwards. Replacing in axle pairs helps keep braking and steering feel even left-to-right. After fitment, expect a crisper turn-in, better straight-line tracking, and tyres that wear the way they should—handy for keeping your rego/WOF inspections stress-free.

Popular questions about 2018 Subaru Impreza control arms

How long do the control arm bushes and ball joints typically last?
In local conditions, many Imprezas see 80,000–150,000 km before wear becomes noticeable, but it varies with road quality and driving style. Lots of corrugations, potholes, or kerb hits can shorten that window. Regular inspections during routine servicing catch issues early.

Do I need a wheel alignment after replacing a control arm?
Yes. Changing a control arm or its bushes alters suspension geometry. A proper four-wheel alignment restores camber, caster, and toe so the car tracks straight and tyres wear evenly.

Is it better to replace just the bushes or the whole control arm?
Both approaches work. Pressing in quality bushes is cost-effective if the arm and ball joint are in great nick. A complete arm with bushes and ball joint pre-fitted reduces labour and tools needed, and is often preferred when multiple components show wear.