Abstract: In a final drive gearing of a power transmission unit, which comprises a drive pinion shaft supported by a pair of axially spaced bearings carried on an upright partition wall of a trans-axle casing and including a pinion in mesh with a crown wheel, an abdominal cavity is provided on the partition wall to receive lubrication oil dipped up by rotation of the crown wheel, and a lateral hole is provided through the partition wall to communicate the cavity into an annular space around the drive pinion shaft between the bearings.

Abstract: A power transmission unit comprises a trans-axle casing provided therein with an upright partition wall for subdividing the interior of the casing into front and rear chambers and having a cover plate for closing in a fluid tight manner the forward open end of the front chamber, a differential gear unit arranged within the front chamber and having a pair of side-journals rotatably supported by a pair of spaced bearings carried on a pair of carrier portions of the casing, and a crown wheel integral with the differential gear unit and in mesh with a drive pinion of a final drive gearing to drive the differential gear unit. The cover plate is provided at its inner wall integral with a pair of lateral protrusions or ribs extending downwardly from an upper portion of the cover plate toward each side-journal of the differential gear unit at both sides of the crown wheel to receive lubricating oil flowing around the crown wheel and induct it to bearing portions of the side-journals.

Abstract: A final drive gearing of a power transmission unit comprises a drive pinion shaft supported by a pair of axially spaced bearings carried on an upright partition wall of a trans-axle casing and a drive pinion integral with the drive pinion shaft and in mesh with a crown wheel for driving a differential gear unit. In the trans-axle casing, an axial cavity is provided on the partition wall adjacent the drive pinion shaft and opens toward the crown wheel to receive therein lubrication oil dipped up by rotation of the crown wheel, a lateral hole is provided through the partition wall to communicate the cavity into an annular space around the drive pinion shaft between the bearings, and a projecting rim is further provided on the partition wall for surrounding upper and side opening edges of the cavity to collect the lubrication oil into the cavity.