How to Test a CV Jointby Nathan Fisher
Constant velocity, or CV joints are found on all front-wheel drive vehicle axles as well as many rear- and four-wheel drive models. CV joints function similarly to universal joints as they allow the front axle half-shafts to independently turn and rotate. CV joints fail for one of two reasons: The rubber boot that protects the joint from road contaminates fail, or they just wear out. Almost universally, the outside joint closest to the wheel will wear out before the inside joint as it is subject to more stress as the vehicle’s wheels turn. If the boot becomes damaged, the joint will usually fail within 3,000 miles.
Examine the rubber boots located on the axle shaft next to the wheel. If it show signs of damage or is covered with grease, the boot has been compromised.
Accelerate and decelerate quickly, but smoothly, taking note of any lurching or shuddering located in the axles while listening for a “clunking” sound. Turn the steering wheel all the way to one side and slowly accelerate, turning in a sharp circle. Repeat in the other direction. Any loud clicking, snapping or popping sounds is an indication of a bad joint.
Lift the vehicle up with the jack and set it on the jack stands, along the frame of the vehicle so the stands will not interfere with the axle rotation. Place one hand on each side of the CV joint and twist the axle back and forth in opposite directions. If it feels excessively sloppy or makes clicking sounds, the joint needs to be replaced.