Your Selected Vehicle
Parts for your 2018 Subaru Outback-Control arms
Explore 4WD & Adventure
2018 Subaru Outback control arms — what they do and how to look after them
Control arms are absolutely used on the 2018 Subaru Outback. Technical references including the Subaru Factory Service Manual (2018 Outback/Legacy, Chassis — Front and Rear Suspension), Subaru New Car Features guide for the BS-series Outback, and OEM/aftermarket parts catalogues (listing complete front lower control arms/transverse links and rear double-wishbone arms) confirm the vehicle runs a MacPherson strut front end with a lower control arm (also called a transverse link) and a rear double-wishbone arrangement using multiple control arms and links.
On a 2018 Subaru Outback, the control arms keep the wheels located precisely while the suspension moves. Up front, the lower control arm ties the wheel hub to the subframe, setting critical geometry for camber and caster, and letting the strut do its job. Out back, the double-wishbone layout uses control arms and links to keep the tyre square to the road, which is a big part of the Outback’s planted, sure-footed feel on both highway and rough Kiwi and Aussie backroads.
When the arm bushes or ball joints wear, owners may notice clunks over bumps, wandering steering, vague turn-in, or uneven tyre wear. Braking can feel a touch unstable if the rear hydraulic bush in the front arm starts to crack or leak. Because bushes are rubber (often fluid-filled), they naturally harden and split with age, heat, and harsh roads.
Good servicing practice for 2018 Outback control arms includes a visual and pry-bar bush check every service or 10–15,000 km, plus a road test for knocks and steering feel. In coastal or high-corrosion areas, inspect the arm shells for rust. Any tear, oil seep from a hydro-bush, or free play at a ball joint means replacement.
- Replace arms in axle pairs when practical to keep alignment behaviour even.
- Choose quality arms: genuine-style hydro bushes ride best, performance polyurethane bushes sharpen response but add some NVH.
- Always torque fasteners at normal ride height to avoid preloading the bushes.
- Fit new self-locking nuts/bolts where the manual specifies, and follow factory torque values.
- Finish with a four-wheel alignment, set toe and verify camber/caster are in spec.
DIY-savvy owners can handle bolt-in complete arms, but pressing individual bushes needs the right tools. If there’s any doubt, a qualified technician should take it on. Regular checks keep the Outback tracking straight, protect tyres, and maintain that confident Subaru handling — all boxes ticked for a smooth roadworthy or WOF.
Popular questions about 2018 Subaru Outback control arms
How long do the control arm bushes typically last?
For many 2018 Outbacks, original bushes commonly last 80,000–150,000 km, depending on road conditions and driving style. Frequent corrugations, heavy loads, or lots of stop–start work can shorten that window. Regular inspections will catch small cracks or fluid seep early.
Can worn control arms cause vibration or uneven tyre wear?
Yes. Excess play in bushes or ball joints lets the wheel change toe and camber as it rolls, which can show up as vibration, feathered edges, or rapid inner/outer shoulder wear. If tyres start wearing oddly, check control arms, then align it once repairs are done.
Do you need a wheel alignment after replacing control arms?
Absolutely. Any change to arms or bushes alters suspension geometry. A four-wheel alignment ensures toe is correct and camber/caster are back within spec, protecting tyres and restoring straight-line stability and steering feel.
