Parts for your 2020 Subaru Legacy-Control arms

2020 Subaru Legacy control arms — what they do and when they need attention

The 2020 Subaru Legacy is fitted with control arms. Technical sources including the Subaru 2020 Legacy Service Manual (Front and Rear Suspension sections), Subaru Global Platform technical brief, and genuine parts catalogues confirm a MacPherson-strut front end with an L‑shaped lower control arm, plus a rear multi-link/double-wishbone layout that uses lower control arms and lateral links. That means control arms are absolutely relevant on this BT‑chassis Legacy.

On this model, the control arms locate the hub and wheel so the suspension can move up and down while keeping geometry in check. The front lower arms carry the load from the strut and tie into the subframe via bushes, while the ball joint mates at the knuckle to allow steering and suspension travel. At the rear, the lower arms and links set toe and camber, stabilising the car under braking and through bumpy corners. When the bushes age or the arm is bent, the Legacy can start to wander, wear tyres unevenly, or feel a bit crashy over corrugations.

There’s no strict replacement interval, but it’s smart to have the control arm bushes and ball joints inspected at each service or every 20,000–30,000 kilometres, especially if the car sees rough roads, towing, or coastal exposure. Many workshops choose complete arm assemblies to refresh bushes in one go, the ball joint is inspected and replaced as required. Always replace in axle pairs and finish with a proper wheel alignment. Bush bolts should be torqued at normal ride height to avoid preloading the new bushes.

• Common signs: clunks over sharp bumps, steering shimmy under braking, tramlining or wandering, uneven inner/outer tyre wear, torn rubber bushes, or a weeping/hydraulic rear bush.
• Good practice: new self-locking hardware where specified, check sway bar links while in there, and wash the underbody after beach trips to slow corrosion.

Typical lifespan for control arm bushes on a 2020 Legacy is often 80,000–150,000 kilometres in Aussie and Kiwi conditions, but driving style and road quality make a big difference. Keeping tyres correctly inflated and getting alignments checked after any hit to a pothole will help the arms and bushes last longer.

Popular questions

Does the 2020 Subaru Legacy have control arms front and rear?
Yes. Technical documentation for the BT‑chassis shows front MacPherson struts with lower control arms and a rear multi-link/double‑wishbone arrangement with lower control arms and lateral links. Parts catalogues list front lower control arm assemblies (left and right) and rear lower arms for this model year.

How long do the control arm bushes last on a 2020 Legacy?
In local conditions, many see 80,000–150,000 kilometres before noticeable wear, but it varies with road surfaces, heat, payloads and driving style. Regular inspections and timely alignments after impacts help extend life.

Do control arm replacements require a wheel alignment?
Yes. Any time a control arm, bush, or related hardware is replaced, a wheel alignment is recommended. It restores correct camber and toe, prevents rapid tyre wear, and keeps the Legacy tracking straight.