Spool Shim Adapter

The MARK WILLIAMS Spool Shim Adapter (MPN 57510) is an essential component for builders and mechanics focused on achieving precise gear alignment and optimal pinion angle geometry in high-performance axle assemblies. This adapter serves as a vital interface within spool-equipped differentials, allowing for fine-tuning of bearing preload and housing centerline positioning.

Constructed to meet MARK WILLIAMS' high standards, the Spool Shim Adapter enables controlled thickness adjustments that directly influence carrier bearing preload, minimizing unwanted play and lateral movement under load. Its compact design measures 5.05 inches in length, 2.9 inches in width, and 1 inch in height, ensuring a seamless fit into standard differential housings while preserving the integrity of spool carrier assemblies.

Ideal for builders working with Mark Williams spools, locker conversions, or custom axle builds, this shim adapter is crucial where precision bearing preload is essential. Installation requires disassembly of the axle housing and proper setup with a dial indicator to ensure accurate measurements.