Parts for your 2015 Subaru Legacy-Control arms

2015 Subaru Legacy control arms — what they do and when to replace them

Control arms are absolutely used on the 2015 Subaru Legacy. Technical references including the Subaru Factory Service Manual for the 2015 Legacy/Outback (Chassis: Front Suspension FS, Rear Suspension RS) and the Subaru OEM parts catalogue confirm the platform runs a MacPherson-strut front end with a front lower control arm (often called a transverse link), and a rear double-wishbone layout with control arms and lateral links. Aftermarket catalogues from major brands also list complete front lower control arm assemblies and rear control/lateral arms for this BN/BS generation.

On this Legacy, the control arms connect the wheel hub/knuckle to the body, keeping the wheel located in the right place through bumps, braking and cornering. The front lower arm carries a ball joint at the knuckle end and big rubber compliance bushes at the subframe end to tame vibration and impact harshness. At the rear, the double-wishbone uses upper arms and lateral links to control camber and toe precisely, helping the car hold a tidy line and look after tyre wear.

Owners often first notice worn control arm components as a dull clunk over sharp bumps, steering wander or tramlining, shudder under braking, uneven tyre wear or alignment that won’t stay put. A visual check may show cracked or torn bushes, or perished dust boots at the ball joint.

Good practice for a 2015 Legacy is to inspect control arms, bushes and ball joints at regular services (at least every 20,000–30,000 km) and after any hard kerb strike or pothole hit. Replacement is straightforward for a trained tech, but there are a few gotchas:

• Always torque control arm bush bolts at normal ride height to avoid preloading the rubber.
• Replace in axle pairs where practical to keep handling balanced.
• Budget for a four-wheel alignment straight after any arm, bush or ball joint work.
• Consider complete arm assemblies if bushes and ball joints are both tired, it can be more cost-effective and quicker.
• Use new self-locking nuts/bolts where specified in Subaru documentation.

Quality OEM or reputable aftermarket arms restore steering feel and braking stability, and they’ll help protect tyres from premature wear. With the Legacy’s suspension geometry doing a lot of the car’s handling heavy lifting, healthy control arms make a noticeable difference on everyday Kiwi and Aussie roads.

Does the 2015 Subaru Legacy have control arms front and rear?

Yes. The front uses a lower control arm (transverse link) with a ball joint and large rubber bushes. The rear double-wishbone uses control arms and lateral links that manage camber and toe. This is confirmed by Subaru’s 2015 Legacy/Outback service manual and OEM parts listings.

How long do control arm bushes typically last on a 2015 Legacy?

It varies with use, but many owners see 80,000–150,000 km. Lots of city kerbs, rough country roads or frequent heavy braking can shorten that. Regular inspections catch small bush cracks before they become clunks, wobbles and tyre wear.

Can the bushes or ball joint be replaced, or is a full arm swap better?

Both approaches are valid. Pressing in new bushes (and replacing the ball joint where separable) can save money on parts, but a complete arm often saves labour time, includes fresh bushes and joint, and can be more reliable if multiple components are worn.