A DBS drive unit pinion drive gearbox design, shown in the picture on the left, does not include a lower pinion support bearing. The DBS pinion drive gearbox is designed so that the bearings of the gearbox itself are sufficient to support the side load on the shaft. Many manufacturers do include a lower pinion support bearing, as shown in the picture on the right. There are multiple shortcomings with this design. First, the bearing is located at the lowest point in the main gear housing, increasing the probability that it will be submerged in water and other debris that settle to the bottom of the housing. The lower bearing is also difficult to access when it fails; significant disassembly of the drive is required to get access to the bearing.