Which of the following is NOT a sign of suspension system defects?

A properly functioning suspension system is crucial for the overall safety and handling of a vehicle. Shock absorbers play a key role in maintaining ride quality by controlling the impact and rebound movement of the vehicle's springs and suspension. If shock absorbers are working correctly, they help stabilize the vehicle, improve traction, and enhance control, thereby preventing excessive bouncing and swaying.

In contrast, the other options indicate potential issues with the suspension system. Leaking fluids can suggest problems like worn seals in the shocks or struts, which can compromise the system's performance. Worn tires can result from improper alignment or suspension issues, leading to uneven wear patterns that can significantly affect vehicle handling. Loose U-bolts can lead to severe safety risks by allowing the axle to shift, affecting the vehicle's stability.

Thus, the answer accurately identifies that properly functioning shock absorbers do not indicate a defect in the suspension system, while the other options point towards issues that can negatively impact vehicle performance and safety.