PURPOSE: To make installation so easily by connecting a driving gear of a lubricating oil floating rotary pump attached to the outside of a geared reversing gear case, to a reduction pinion in mesh, while setting up an oil pressure adjusting governor valve of a hydraulic clutch at the case outside.

CONSTITUTION: A governor valve 41 is connected, in mesh, to a driving gear 33 of a lubricating oil floating rotary pump 35 at the outside of a geared reversing gear case 11. Consequently, even in the case of attaching the governor valve 41 afterward, any disassembly of the whole body of the reversing gear case 11 is no longer required. In addition, since the driving gear 33 is connected to a reduction pinion 18 in mesh, not being installed in a gear 15 on an output shaft, the overall length is in no case lengthened as well. Moreover, it is set up in a relatively higher position so that any work for maintenance or the like also will not come to be difficult because of being interrupted by a setting leg.