BACKING FRAME

550 468 87F BACKING FRAME This frame bearing carries the heavy radial and axial loads generated during drilling. Its main job is to support a major rotating or sliding assembly within the drifter or feed, maintaining precise alignment between critical components. By reducing friction and absorbing vibration, it allows the internal mechanics to transfer energy efficiently to the drill string.

A worn or failing frame bearing can lead to serious internal damage. When this bearing develops excessive play, it causes misalignment of the drive train, leading to reduced impact energy and slower penetration rates. This misalignment also puts extra stress on gears, seals, and the shank adapter, accelerating wear on these more expensive parts.

Listen for grinding noises or feel for excessive vibration from the drifter, as these are common signs of a worn bearing. During an inspection, check for any side-to-side play in the shank adapter. If you find any, it's a strong indicator that this bearing needs to be replaced promptly to prevent a major failure.