What the bush does
The front lower control arm locates the bottom of the wheel hub and controls where the wheel sits under braking and cornering. It bolts to the subframe through rubber-and-steel bushes that let the arm pivot while absorbing road noise and vibration.
Most cars have two per arm — a front bush and a larger rear bush, which is usually fluid-filled or heavily voided and is almost always the one that fails first.
Symptoms of worn control arm bushes
- A dull clunk or knock over speed bumps and potholes
- Steering that feels vague, wandery or slow to centre
- Shudder or judder through the wheel under braking
- Uneven or feathered wear on the inside edge of the front tyres
- The car pulling to one side, or an alignment that will not hold
- Visible cracking, splitting or weeping fluid on the rubber
How it gets diagnosed
Bushes are checked with the suspension loaded and again with a pry bar to look for movement in the arm relative to the subframe. Split rubber is obvious; a collapsed fluid-filled bush can look fine and still be shot, so movement matters more than appearance.
Worn bushes are frequently blamed for what is actually a failed ball joint, sway bar link or strut mount, all of which make a similar noise. A road test plus a hands-on inspection separates them — replacing the wrong part is the most common outcome of guessing.
Bushes only, or the whole arm?
Pressing new bushes into the existing arm is cheaper on parts but needs a press and, on some designs, considerable labour. On many modern cars a complete control arm with bushes and ball joint already fitted costs little more than the bushes alone and takes a fraction of the time.
We will price both ways for your car and tell you which one actually makes sense rather than defaulting to the dearer option.
Always do a wheel alignment afterwards
Replacing a control arm or its bushes changes camber and caster. Skip the alignment and you will chew out a set of front tyres in a few thousand kilometres, which costs more than the alignment several times over.
Bushes should also be torqued at ride height, not with the suspension hanging — do it wrong and the new bush is pre-twisted and tears itself apart early.
Is it safe to keep driving?
A slightly perished bush is a noise and a tyre-wear problem rather than an emergency. A badly collapsed or completely separated one lets the wheel move under braking and is genuinely dangerous, and it will fail a safety certificate. If the clunk is loud or the steering has gone noticeably loose, get it checked before you drive far.
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