Will new control arms improve ride quality?
Besides being stronger than stock control arms, upgraded control arms can improve the truck's ride quality. Most kits offer a smoother and better ride than the factory models for both on-road and off-road driving. Additionally, replacement control arms will often weigh less than stock control arms. via
Do you need aftermarket lower control arms?
It is not necessary to replace both lower or both upper control arms if one is bad, but often they wear out at roughly the same mileage. If one control arm is bad and the other is on its way, it makes sense to replace both arms at once. This way, you only need to do the wheel alignment once. via