Bissell Geared Large Belt - 1548 Pro Heat Revolution - Fits 1986

Part 1606418 is the large geared belt in the Bissell ProHeat Revolution, the toothed belt that drives the brush roll on the 1548, 1550, 1551 and 3579. The listing also covers the 1986 Revolution Pet Pro, which uses the same large belt.

Geared belts do not slip the way a flat belt does, so the failure looks different: instead of the brush slowing down, teeth shear off and the roller stops dead while the motor keeps running. You will hear the pitch change, see clean water going down without the brush turning, and find shed rubber teeth in the bottom of the nozzle. Carpet comes up wet and matted rather than groomed.

Check the belt whenever you clear hair off the brush roll. Cracks running down into the roots of the teeth mean it is close to going, even if none have broken off yet.