A change-speed gearing assembly including upper and lower bearings carried on a partition wall of a casing for the assembly respectively for supporting thereon input and counter shafts, and a bearing retainer secured in a fluid-tight manner to the outside face of the partition wall to retain both the bearings in place. The input shaft extends outwardly through an annular seal member carried on the upper portion of the bearing retainer coaxially with the upper bearing. The bearing retainer is formed with upper and lower cavities and is formed at one side thereof with a vertical groove which opens at its upper end into a side portion of the upper cavity located above the lower edge of the seal member and at its lower end into the upper portion of the lower cavity to maintain the level of lubricating oil in the upper cavity above the lower edge of the seal member.