How many ball joints are found in a short-long arm (SLA) front suspension?

In a short-long arm (SLA) front suspension system, there are two types of control arms: the upper control arm and the lower control arm. Each of these control arms typically has its own ball joint to facilitate the connection between the suspension and the steering knuckle, allowing for vertical movement of the wheel while still maintaining a connection to the chassis.

Therefore, in the case of an SLA suspension setup, there are indeed two upper and two lower ball joints, as each control arm has one ball joint at the chassis side and one at the wheel side. This gives the SLA system its characteristic design that enhances ride quality, handling, and adjustability of camber angles, making it a common choice in many vehicles.

While other options may suggest varying numbers of ball joints, the complete function of a typical SLA suspension and the presence of both upper and lower control arms make the two upper and two lower configuration the accurate representation of ball joints in this system.