The Safe-T-Pull Original Cable Spring is a replacement part that centers your pulling arm behind the towing vehicle. Over time they can wear out, causing the pulling arm to be misaligned, making hook up difficult. You may need to replace your springs if there are cuts, scratches, or scrapes. Also, check to be sure the spring is fully retracted without any tension on them.
When the puller arm is resting on the ground no gap should be visible. If any gap is visible your spring has exceeded its maximum weight limit and should be replaced immediately.