Control Arm Kit with Fitting Position Front and Rear, Front, Rear

A control arm kit supplies the arms as finished assemblies rather than as parts to build up. The bushings are already pressed in, the ball joints are already fitted where the design uses them, and the whole thing bolts into the factory mounting locations.

Some kits are straight replacements for arms that have worn out. Others have geometry correction built into them, which is what a lowered car or a lifted truck needs once the factory adjustment has run out.

Why a Complete Assembly Beats Rebuilding What You Have

If your arms are straight and the only problem is tired rubber, a control arm bushing kit is cheaper and there is no reason to spend more. That is the honest starting point.

The math changes as soon as more than one thing has worn. The arm has to come off the car whichever repair you choose, so the teardown, the alignment and most of the labor are identical whether you are pressing in bushings, driving out a ball joint, or bolting on a control arm assembly. Once both ends of the arm are due, the press time and the risk of damaging an arm eye usually make the complete kit better value even where a rebuild is technically possible.

There are also situations where rebuilding is simply not on the table. A bent or heavily corroded arm cannot be saved. A mounting eye that has worn oval will not hold a new bushing no matter how carefully it is pressed in, and you will find that out after the new bushing works loose rather than before. Check the eyes before you commit to a rebuild.

And on a great many modern cars the ball joint is pressed or riveted into the arm and is not separately serviceable in any practical sense, which means a worn joint has already decided the question for you.

What Arrives Assembled, and What That Saves You

The value of a control arm and ball joint assembly is not really the parts. It is everything you avoid doing to them.

Pressing bushings out of an arm and new ones back in square takes a hydraulic press, correct diameter tooling and a fair amount of time. Driving a pressed or riveted ball joint out of its housing without damaging the bore takes the same. Both jobs carry a real risk of ruining an arm that was perfectly serviceable when you started, and an arm costs considerably more than the tooling would have.

A complete assembly removes all of it. The old arm comes off, the new one goes on, and the only specialist tool involved is a ball joint separator. For a shop that means less labor on the invoice. For anyone working at home it means the job stays inside what a driveway and a socket set can handle.

The bushings are the other half of the value. Factory rubber deflects under load even when it is new, because it is chosen for quietness rather than control, and it gets steadily worse as it hardens and cracks. An arm running polyurethane bushings holds the geometry where the alignment set it rather than only when the car is parked.

Upper and Lower, and Why They Go Together

On a double wishbone front end the upper and lower arms share the work, and the pair is what determines how camber changes through suspension travel.

That is why upper and lower control arm kits exist rather than just single arms. Replace one and leave the other and you have corrected half the geometry while the other half continues deflecting under load. Worse, a new rigid arm working against a tired flexing one means the two ends of the knuckle now move by different amounts under the same input, so the geometry shifts every time you brake or turn in and the alignment you just paid for is only accurate standing still.

On a strut car there is usually only a lower arm, which does all the positioning work on its own and carries the lower ball joint, so a lower control arm assembly is the whole front end fix on that side. Kits there pair the lower arms across the axle, sometimes with a tension strut or radius arm where the lower suspension is a two piece arrangement.

At the rear, kits group the lateral, camber, toe and trailing arm positions that set rear geometry on an independent setup.

Either way, do both sides. One new arm against one worn one leaves the car with different amounts of compliance left to right, and it will pull under braking regardless of what the alignment reads.

Geometry Correction Built Into the Arm

This is where the range goes past replacement, and it is the reason a lot of people end up here.

Fixed offset arms have the correction designed into the shape of the arm, so the camber or caster change is built in and cannot move. They are right the moment they are bolted in, there is nothing to check or adjust later, and nothing can work loose. On a truck at a known lift height, that reliability is usually what you want.

Adjustable arms let the setting be dialed in on the alignment rack and allow each side to be set differently, which matters on a car that has settled unevenly or pulls to one side with tires and pressures ruled out. They also give you room to change ride height later without buying arms again.

Geometry correction kits go further still, addressing roll center and bump steer rather than just the alignment numbers. Lowering a strut car changes the lower arm angle, which drops the roll center, often faster than it drops the center of gravity. The gap between them grows, there is more leverage rolling the body, and the car ends up leaning more than it did at stock height despite stiffer springs. Correcting the arm geometry fixes the cause rather than adding sway bar to treat the symptom.

Check the lift or drop range each kit was designed around, because an arm engineered for one ride height fitted to a very different one moves the geometry in a direction you did not ask for.

Ours Come Apart Again When the Time Comes

Most aftermarket control arms are sold as sealed units. The joint is pressed in at the factory, and when it eventually develops play the entire arm is scrap, including a perfectly good body, the bushings and whatever correction geometry you paid for.

Ours are built to be serviced. Bushing and ball joint service kits are available for the arms in this range, so a high mileage arm gets refreshed rather than thrown away and the geometry correction stays bought.

On a car that gets driven hard, tracked, or covers real miles, that is the difference between buying arms once and buying them repeatedly.

Where a Kit Is the Wrong Purchase

Worth being straight about the cases where you should keep your money.

If the arms are straight, the eyes are round, the ball joints are tight and only the bushings have perished, buy the bushing kit rather than upper and lower control arms you do not need. If the ride height is stock and the alignment is within spec, you do not need correction arms and fitting them will move the geometry away from where it should be. And if the car is being sold shortly, the labor in a full front end refresh is hard to justify against what you will recover.

A correction arm on a stock height car is the most common mistake here. Those arms exist to hand the aligner range that a modified car has lost. On an unmodified car, they solve a problem you do not have.

Separators, Torque at Ride Height and the Alignment After

Arms bolt into the factory locations and arrive assembled, so this is a remove and replace job rather than press work.

Support the car properly and take the load off the suspension before separating a ball joint, because a joint under spring load releases suddenly and without warning. Use a proper ball joint separator rather than a hammer, since hammering damages the knuckle bore and the stud threads.

Torque the inner fasteners with the car back on its wheels at ride height rather than hanging at full droop. Whatever position a bushing is clamped in becomes its neutral position, so an arm torqued at droop spends its life twisted and the bushings bind from the first mile. This is the most common mistake made on control arm work and it costs nothing to avoid.

Fit a new cotter pin to the castle nut rather than reusing the old one.

Book the alignment for the same visit. On a correction or adjustable kit the entire point is to give the aligner range, so driving away unaligned wastes the exercise. Set adjustable arms roughly beforehand and let the aligner make the final call with the machine reading the numbers, and tell them what the car is used for, since a street alignment and a track alignment are different targets.

Find Control Arm Kits for Your Vehicle

Pick your position with upper control arm kits or lower control arm kits. Want the joint pre-fitted? A control arm assembly with ball joint bolts straight in.

Select your vehicle to see the control arm kits available for it, and check each listing for whether ball joints are included, how much correction it provides, and the ride height it was designed around. Every Whiteline component is backed by our warranty, a fitment guarantee and 60 day returns.