A gearhead assembly between a drive shaft and an output shaft of a trimmer arranged parallel but staggered to one another, includes a bearing shaft extending perpendicularly between the drive shaft and the output shaft. The bearing shaft has a first end supported in the first housing part and a second end supported in the second housing. A central gear is mounted on the bearing shaft. A clamping device has a clamping shaft that has a first and a second opposed ends engaging the first and second housing parts. The second housing part together with the output shaft is pivotable about the bearing shaft relative to the first housing part in a plane parallel to the axial direction of the drive shaft. The bearing shaft is a hub, and the clamping shaft penetrates the hub.