GM ASEP Steering and Suspension Practice Test 2025 - Free General Motors Automotive Service Educational Program Practice Questions

The reason driving in reverse while turning is the most effective road test for identifying defective outer constant velocity (CV) joints has to do with the operational conditions that CV joints endure during such movements. When a vehicle moves in reverse while turning, it places significant strain on the outer CV joints, as these joints are responsible for accommodating the changes in angle and maintaining torque from the drive axle to the wheels.

Under these circumstances, if the outer CV joint is defective, the driver may notice symptoms such as clicking or popping sounds, vibrations, or a lack of smooth operation in the vehicle's motion. These symptoms arise because a faulty CV joint cannot properly handle the angular displacement required when turning, especially when the vehicle is in reverse. This specific test effectively replicates the stresses and angles that the CV joints experience during typical driving scenarios, making it easier to diagnose issues.

Other road tests, while valuable for checking overall vehicle performance and stability, do not specifically target the typical operational challenges faced by outer CV joints in the same manner. For example, driving on a bumpy road may indicate suspension issues but is less effective for CV joint diagnosis. Similarly, driving slowly into a driveway with a curb may not sufficiently engage the CV joints at the necessary angles, and driving beside parked