Individual Upper Control Arms

These are single upper control arms rather than pairs, supplied for the side and position they suit, with the bushes and ball joint already fitted.

They are repair parts rather than correction parts. One upper control arm has worn out or been damaged, the other has not, and there is no reason to buy two.

What Does an Upper Control Arm Do, and Why Does One Side Go First

The upper control arm holds the top of the steering hub while the lower arm holds the bottom, and between them they set camber and caster. It also carries the upper ball joint the hub pivots on when you steer.

On most double wishbone designs the upper arm carries less vertical load than the lower one, because the spring sits on the lower arm. What it does take is the sideways and twisting load from cornering, braking and steering, and all of that feeds through a ball joint that is typically smaller than the one underneath.

That is why these fail the way they do. The wear concentrates in the joint rather than spreading evenly across the front upper control arm bushes, and a joint fails when its boot splits rather than when the vehicle reaches a particular distance.

Boots tend to split one at a time rather than together. A stone, a bit of corrosion, or simply one side sitting in more weather than the other, and one joint is contaminated while the other stays sealed and healthy for years longer.

Why a Single Upper Control Arm Is Often the Right Buy

That failure pattern works in your favour, because one side needing replacement while the other is genuinely sound is a normal outcome on an upper arm rather than an unusual one.

Perished bushes tend to arrive as a pair, since rubber ages on a calendar and both sides have sat through the same summers. A torn boot on a front upper ball joint is usually a single event on a single corner.

Impact damage is the other single sided case. A kerb strike or a hard pothole bends one arm, and the tell is an alignment that has never been right since, with one side reading out of specification while the other is fine.

Some vehicles also use left and right upper control arms that differ from each other, so an individual arm is the only way to order the one you actually need.

Upper Control Arm Ball Joint Replacement or a Complete Arm

This decides what you buy, so it is worth checking before ordering.

Where the ball joint bolts into the arm, upper control arm ball joint replacement is a job on its own and the arm stays on the vehicle. That is the cheapest route when the arm is straight and the bushes are sound.

Where the joint is pressed or riveted into the arm, it is not separately serviceable in any practical sense. A worn joint means a new arm, and on plenty of vehicles that is the only option regardless of what the arm itself looks like.

An upper control arm bushing service set covers the middle case, where the joint is still tight and only the bushes have perished. That suits a vehicle where you have caught the wear early, and it keeps a good arm on the vehicle rather than replacing it.

Check the Other Upper Control Arm Before You Order

Worth a few minutes, because it changes what you order and it is easy to get wrong by assumption.

With the vehicle safely supported and the suspension unloaded, rock the wheel top to bottom and watch the upper joint. Any play there means the joint has gone, so do the same on the other side and compare, because the comparison tells you more than either result on its own.

Check both ball joint boots while you are underneath, because a split boot on one side with an intact boot on the other points at a single failure. Two perished boots means both joints have been taking water and grit for a while, and the second one will not be far behind the first.

Then lever the arm against its mounts and look for movement at the bush rather than flex in the arm. If one front upper control arm bushing is squeezed out and the other is intact, you have a single sided problem.

Replacing Upper Control Arms in Pairs When the Wear Is Age Related

If the wear is age related, buy two.

Both arms have covered the same distance in the same conditions, so perished bushes on one side almost always means the other is close behind. The vehicle is already up, the wheel alignment is already being paid for, and adding the second arm now costs far less than a separate visit in six months.

There is a driving reason on top of the cost one, because a new arm with fresh bushes is rigid while the old one still has compliance in it, so under load the two sides deflect by different amounts and the vehicle can feel slightly uneven even with a correct alignment. On a vehicle where the other arm is genuinely healthy that difference is negligible. On a higher kilometre vehicle it is noticeable.

Replacement Arms and Correction Arms Are Different Purchases

Both get called upper control arms and they are bought for completely different reasons, so it is worth being clear.

The arms in this range are direct replacements built to factory geometry. They go on a vehicle sitting at standard ride height and restore the alignment it is supposed to have, which is what you want when a ball joint has failed, a boot has torn, the bushes have perished or the arm has been damaged.

Correction arms are a different product entirely, with offset built into them to recover camber and caster on a raised vehicle, and they are always fitted as a pair, because a corrected arm working against a factory one gives you two different geometries and an alignment nobody can balance.

If you are here because of a lift kit and an alignment the workshop cannot bring into specification, a fixed offset or adjustable arm is the part you need rather than a standard replacement. A replacement arm puts the geometry back exactly where the lift already moved it.

Ordering Upper Control Arms by Side and Position

Order by side and position rather than by eye, since left and right upper control arms can look near identical in a photograph and be entirely different parts.

Check the listing for front or rear as well, because a rear upper control arm on an independent rear end does a different job to a front one and the parts are not interchangeable.

Work out which corner you need before ordering. If a joint has failed the tell is usually obvious once the vehicle is in the air, with play at that corner and often a split boot or grease thrown around the inside of the wheel.

Check what fasteners are included as well, since some applications reuse the original upper control arm bolt and some supply new hardware, and finding that out before the vehicle is apart saves a trip.

Signs You Need One Upper Control Arm Rather Than Two

• Play at one upper ball joint with the other still tight
• A split or torn boot on one side with the other intact
• Grease thrown inside one wheel arch and not the other
• Knocking from one corner over bumps, consistent to that side
• One side reading out of specification on the alignment printout
• Tyre wear noticeably worse on one front corner
• Visible damage to one arm after an impact
• A previous repair that already replaced the opposite arm
• One mounting eye worn oval while the other is round

If both sides show the same symptoms at similar levels, that is age and you are looking at a pair.

Separating the Upper Ball Joint and Torquing at Ride Height

A complete upper control arm kit bolts into the factory mounting locations and arrives assembled, so this is a spanner job rather than press work.

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

Torque the inner fasteners with the vehicle back on its wheels at ride height rather than hanging at full droop. Whatever position a bush is clamped in becomes its neutral position, so an arm torqued at droop spends its life twisted and binds from the first kilometre.

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

Get a wheel alignment afterward without exception, because replacing an upper arm changes camber and caster immediately, and when you have only done one side the alignment is what confirms the two sides now match each other.

Find Individual Upper Control Arms for Your Vehicle

Select your vehicle to see the single upper control arms available for it, and check each listing for the side and position it suits along with whether a ball joint is included. Every Nolathane component is backed by our warranty, a fitment guarantee and 60 day returns.