SEBO Drive Cog Spring for the Duo

Between the brush drive cog and the bearing block sits a small spring whose only job is to keep constant pressure on that connection. SEBO lists it as part 3028 and draws it at position 67 of the Duo parts diagram, with the pulley at 66, part 3009, on one side and the brush drive cog at 68, part 3007, on the other.

Springs lose tension gradually, which is what makes this one awkward to diagnose. When it relaxes, the cog is free to shift a fraction under load and the drive begins to skip or rattle in a way that looks exactly like gear damage but is not. Owners often replace the cog, find the noise still there, and only then work back to the spring. The reverse case is worth knowing too: a spring that has broken outright will let the cog wander far enough to chew its own teeth, so a stripped cog is a reason to inspect the spring rather than simply fit a new cog.

• Part number: 3028
• Diagram position: 67 on the SEBO Duo parts diagram
• Location: between the brush drive cog and the bearing block
• Fits: the SEBO Duo brush machine
• Sold: individually
• Related numbers: 3009 pulley at 66, 3007 brush drive cog at 68, 3074HG bearing block at 69, 3052HG bearing block assembly LH at 70

Because it is a small item that is easy to overlook, many owners add one to the order whenever the drive side of the machine is being opened up for other work, rather than reaching the bench and discovering the old spring has gone slack with the machine already in pieces. Searches for a SEBO Duo spring, a drive cog spring or part number 3028 all resolve to this component. Genuine SEBO spare through an authorized dealer. Ships in 2-5 business days.