A spreader implement and drive gearbox therefor are provided that incorporate a single gearbox for driving both a distributor assembly for throwing manure and the like out of the spreader implement and for driving a transporting assembly for moving the manure or the like toward the distributor assembly. The single gearbox provides direct gear drive of one of the assemblies. The drive gearbox may include one or more biased clutch assemblies for clutching or varying the driving speed transmitted by the gearbox.