The firmness the Nissan control arm has in controlling of the lateral movement of the front wheel is why cars equipped with this suspension component will handle better than those that don't. This is the suspension part that is connected to the lower portion of the wheel assembly and the frame of your Nissan.
The control arm limits the movement of the spindle because the other end of this suspension part is connected to the frame of the vehicle. The amount of this movement is less than 1%. This is an improvement over the A-frame type of system that has a margin of 2% movement.
At the connecting points of the control arm are polymer grommets, or bushings. It is these bushings in the control arm that will wear out over time and cause it to be in need of replacing. This is easy to notice by inspecting this component on your Nissan to see if it can be manually moved by hand. It can also be felt by what will seem to be less control when maneuvering the vehicle. The steering will seem to be looser and sloppier.
The replacement of the Nissan control arm is not a complicated procedure. With the wheel removed, a clear view of the suspension component can be seen. The time this replacement should take is less than an hour if you are skilled enough, and only requires a set of wrenches and a lift or jack.
If one control arm is bad on your Nissan, the other one on the opposite side of the vehicle should also be changed even if it has not gone bad yet. Since it was exposed to the same amount of stress over time, it will be close to having the same amount of wear on it.