What will indicate a failure in the rear wheel alignment?

The indication of a failure in rear wheel alignment is best represented by the obvious misalignment of the rear axle. This misalignment can lead to a variety of issues, including uneven tire wear, poor handling, and compromised vehicle stability. When the rear axle is not aligned properly, it can cause the rear wheels to angle incorrectly, diverging from the intended straight path that the vehicle should follow. This situation often requires adjustment to restore proper alignment, ensuring that the vehicle operates safely and efficiently.

Other options imply conditions that either do not indicate a failure or reflect proper alignment. For instance, when rear wheels follow the front wheels, it typically means that the alignment is functioning correctly, as the rear wheels should track appropriately with the front. Similarly, distance measurements within specifications suggest that the vehicle's setup adheres to manufacturer's standards, which is not indicative of a failure. Lastly, a frame in perfect condition usually suggests that there are no structural issues affecting alignment, making it unlikely for there to be a rear alignment problem if the frame is undamaged.