Wear on the ball joint of the right rear suspension control arm of a Hyundai Sonata Grandeur may manifest itself in the following ways:
Unusual noise: When the vehicle travels over uneven surfaces such as speed bumps or gravel roads, a distinct "clunking" or "thumping" sound may be heard from the chassis. This is caused by increased ball joint play and friction between the metal connectors. If the noise changes with the frequency of the bumps, it typically indicates a damaged ball joint dust cover, with the ingress of mud and sand exacerbating wear.
Abnormal handling: A worn ball joint can disrupt the geometric stability of the suspension system, potentially causing the vehicle to drift sideways while driving straight, requiring constant steering correction. At high speeds, there may also be a noticeable side-to-side sway, which in severe cases can lead to "snaking." Additionally, the steering wheel may feel playful, with sluggish steering response and reduced handling. Abnormal tire wear: A worn ball joint can cause inaccurate wheel alignment parameters, leading to uneven tire wear, such as uneven wear on the inner or outer shoulder, and serrated or wavy tread wear.

Increased bumpiness: A worn ball joint can no longer properly cushion road impacts, causing the vehicle to experience more bumps and vibrations on flat roads, resulting in reduced ride comfort. During emergency braking, uneven force applied to the wheels due to a worn ball joint can cause the vehicle to veer more significantly, compromising driving safety.