In the case of rear rail damage, when must the rail be replaced?

The replacement of a rear rail in the event of damage is primarily determined by the structural integrity and alignment of the vehicle post-collision. When the rear rail exhibits a "mash" condition, it indicates that the material has been significantly deformed or crushed, compromising its ability to maintain the structural integrity of the vehicle. This type of damage typically affects the performance, safety, and alignment of the vehicle.

Sway, sag, and diamond-shaped deformities can indicate damage, but they often suggest less severe deformation than mashing. Additionally, these types of damage can sometimes be repaired or realigned without necessitating a full replacement of the rail. In contrast, when a rail is mashed, it often requires replacement to ensure that the vehicle can be returned to a safe and operable condition. Therefore, a rail that is mashed must be replaced to maintain the vehicle's structural strength and safety features.