Abstract

In a final drive and differential unit comprising a ring gear integral with a differential gear unit rotatably mounted within a carrier, and a drive pinion shaft supported by a pair of axially spaced bearings within a cylindrical support structure of the carrier, the shaft extends outwardly through an oil seal member mounted within an outer end portion of the support structure and is provided at its inner end with a drive pinion in mesh with the ring gear. The support structure is formed at one side thereof with an enlarged portion formed therein with an oil supply passage opening at its one end into the carrier at the same side as the ring gear and is formed at the other side thereof with another enlarged portion formed therein with an oil return passage opening at its opposite ends into the carrier and into a first annular space between the oil seal member and the bearing. The support structure is formed in its side wall with first and second lateral holes respectively for communication between the oil supply passage and a second annular space between the bearings and for communication between the oil supply passage and the first annular space. The lowermost edge of the second lateral hole is positioned below the lowermost edge of the first lateral hole to ensure the flow of lubricating oil into the first annular space passing across the second lateral hole.