Mechanics

Ball Joints

How Ball Joints Work

Ball joints are an important part of the vehicle suspension and steering system. Ball joints are a flexible ball and socket that allows suspension movement in more than one direction that enables positive control over the front wheels at all time. There are commonly upper and lower ball joints that connect each front wheel spindle to the control arms. When driving a car through a turn, the ball joint allows the suspension arms to flex up and down over bumps while another ball joint connects the steering linkage to the steering knuckle on the spindle.

Ball joints are used to connect lower suspension control arm to the steering knuckle on the spindle. When turning, the suspension travels up and down and keeps constant control of the wheels. There are two types of ball joints, sealed units which don't require lubrication, and standard ball joints that require grease to be pumped into a zirk fitting.

Maintenance

When a ball joint becomes worn, they will have a measurable amount of play within the ball and socket. Each manufacturer has an acceptable limit before replacement is required. When driving a car over bumpy roads, the vehicle can jump one way or another after hitting a bump. Ball joints should be inspected regularly.

Common Problems

  • Premature failure is usually the result of poor maintenance.

AUTHOR


Written by
Co-Founder and CEO of 2CarPros.com
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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Article first published (Updated 2013-09-06)