Kirby Geared Primary Drive Belt - Generation 3, G4, G5, G6, Ultimate G, Diamond Edition

Part 554189S is Kirby's geared primary drive belt, and the key fact to know is that it powers the self-propel transmission, not the brush roll. Its teeth engage a toothed gearbox pulley, so the tooth pitch has to be an exact match. A smooth belt made for the brush roll simply will not mesh here, no matter how close the diameter looks.

Wear on this belt shows up as a self-propel that drags rather than a machine that loses pickup. The upright moves forward less readily than it once did, stumbles before catching, or gives up pushing itself across thick pile entirely, all while the brush roll spins normally beneath it. Off the machine, a worn example typically shows shiny tooth faces, cracks running across the ribs, or a tooth or two broken away outright.

Coverage spans Kirby's geared Generation line built around this transmission: Generation 3, G4, G5, G6, the Ultimate G and the Diamond Edition. Worth noting alongside that: the parts listing for this belt carries an explicit warning that a Sentria transmission takes 554105S instead, so a machine outside the Generation range above needs its own part rather than this one.

• Part: 554189S, geared primary drive belt
• Fits: Kirby Generation 3, G4, G5, G6, Ultimate G, Diamond Edition
• Function: powers the self-propel gearbox, separate from the brush roll
• Symptom: self-propel sluggish, hesitant, or absent with the brush roll still turning