The Spring is an OEM part for Whirlpool stand mixers. It is responsible for ensuring proper tension and support in the mixer's internal mechanisms, contributing to the smooth operation and stability of the appliance. You should replace the spring if it becomes worn out, stretched, or damaged. Causes of a bad spring can include regular wear and tear from frequent use, exposure to heavy loads, or physical damage due to impact or mishandling. A faulty spring can lead to reduced stability and efficiency of the mixer.