First gear is antibacklash gear
A cylindrical item having a full 360 degree (6.282 radians) complement of teeth on two or more surfaces. It may be a one-piece casting or composed of two or more separate items firmly held together by welding, rivets, pins, or the like, to form a single unit. It is designed to mount on a shaft. For items consisting of a shaft with an integral complement(s) or gear teeth, see gearshaft (as modified). Excludes gear subassembly, speed decreaser.
Classification: Gears and gearing, other than toothed wheels, chain sprockets and other transmission elements entered separately
NSN 6610-01-152-2821
NSN 6320-00-845-3261
NSN 5999-01-450-0617
NSN 5965-01-180-5468
NSN 5975-00-773-3647
NSN 6620-01-281-6386
NSN 6620-01-581-5301
NSN 6110-00-167-7522
NSN 6650-00-144-4555
NSN 5910-00-191-3813
NSN 5950-00-574-2396
NSN 5915-01-587-5380