In a vehicle power unit, a main shaft and a counter shaft of a transmission are placed in and taken out through an opening formed on the crankcase. In one embodiment, dummy metals are inserted using a place and route tool, where the place and route tool has timing-awareness. The bib has a hole therein which is fitted with an omega clip and a split ring so that the omega clip is held loosely in position by the split ring. For example, the segment data may partition the manufacturing processes along a path traversed by the material within the manufacturing process.