Control Arms

Control arms are the triangulated suspension links that connect the wheel assembly (spindle) to the car's frame or subframe. Classic Mustangs use both upper and lower control arms on the front suspension.

Upper control arms:

• Attach spindle to shock tower

• Control camber (wheel tilt)

• Usually shorter than lower arms

• Subject to less stress

Lower control arms:

• Attach spindle to K-member (subframe)

• Support coil spring

• Control wheel position

• Subject to major stress (weight, braking forces)

What they do:

• Allow wheels to move up and down (suspension travel)

• Maintain proper wheel alignment during suspension movement

• Transfer braking and acceleration forces to chassis

• Keep wheels pointed in the right direction

After 50+ years, the rubber bushings in control arms turn hard, crack, and wear out. When bushings fail, the control arms move in ways they shouldn't, causing:

• Wandering steering (car doesn't track straight)

• Clunking noises over bumps

• Poor handling and stability

• Uneven tire wear

• Alignment that won't stay set

I drove for 6 months with worn control arm bushings before I diagnosed the problem. The car would wander on the freeway—not dramatically, but enough that I was constantly making small steering corrections. After replacing the bushings, the car tracked straight and true. I'd been fighting worn bushings, not wind or road crown.

Control arms affect handling, safety, and tire wear:

Worn factory control arms (original bushings):

• Rubber bushings hardened and cracked

• Excessive play in suspension

• Wandering, vague steering

• Poor cornering stability

• Alignment impossible to set correctly

• Cost to rebuild: $400-$1,200

Rebuilt with new bushings:

• Tight, controlled suspension movement

• Stable steering feel

• Better handling

• Proper alignment possible

• Cost: $400-$1,200 parts + labor

Upgraded tubular control arms:

• Lighter weight (aluminum or steel)

• Better geometry (improved handling)

• Adjustable for custom alignment

• Modern bushings (urethane or spherical)

• Cost: $800-$2,500

The handling reality:

You can upgrade springs, shocks, sway bars, and tires all you want. If your control arm bushings are shot, the car will still handle poorly because the wheels aren't staying where they're supposed to be.

Fix the foundation first, then add upgrades.