515415 Retainer, primary chain adj. lining

This primary chain adjuster lining retainer from MCS is a vital component for the health of your Sportster's primary drive. It is designed to fit late 1958 to early 1980 XL Sportster models and serves as a direct replacement for OEM 39979-58A. This retainer keeps the tensioner lining securely in place, ensuring that the primary chain is properly guided and tensioned. Over time, these retainers can become brittle or damaged, which can lead to excessive chain noise or even catastrophic failure if the lining shifts. Installing this high-quality replacement during your next primary service is a smart way to ensure the longevity and smooth operation of your vintage Ironhead.