What symptom indicates that the inboard CV joint is failing?

The symptom that accurately indicates a failing inboard CV joint is the presence of torn boots. The CV boot serves as an essential protective cover, keeping lubrication contained within the joint while preventing dirt and debris from entering. When the boot becomes torn, it exposes the CV joint to contaminants, leading to accelerated wear and potential joint failure. This exposure can result in premature failure because the joint can no longer maintain its necessary lubricant levels, which is vital for its smooth operation.

While clicking noises during turns are typically associated with CV joint wear, they do not specifically indicate that the inboard joint is failing; this sound might indicate issues with other components as well. Unusual vibrations at high speed can suggest a number of issues, including balancing problems or other drivetrain concerns, not limited to the CV joint. Leaking grease is a sign of a compromised boot or seal but does not directly indicate that the joint itself is failing, as it may still function adequately for a time. Thus, the best answer regarding the failure of the inboard CV joint is the condition of the CV boot itself.