.
With a manual valve body this applies even more so.
All of the combined kinetic energy of the transmission (as transferred from the engine) is absorbed by the sprag. So if/when it comes loose, the sprag can literally spin out of the transmission case with catastrophic effect. To counter the sprag working itself loose, many resort to drilling and tapping the factory sprag, bolting it down in place. Other manufacturers provide what are aptly called a “bolt-in sprag” that are already drilled and tapped, as well as packed with new springs and rollers.
