Bert Transmission Axle Tube 25.063" CTD-017-25-1/16 - Because the drive flange is sunk into the oversize driveshaft tunnel, SmarTubes are shorter than any other axle for the same rear end track width. This length saving also affects the driveshafts that are 3” shorter on a car using SmarTubes. Besides saving weight, this configuration reduces driveshaft torsion and improves throttle response. Unlike some other axles, the SmarTube is CNC machined from a single piece of 7075 aluminum. The result is a very light, strong, and rigid racing axle. Oversized driveshaft tunnel prevents contacts between axles and the driveshaft. This extra space also simplifies driveshaft installation and removal. SmarTubes are designed to operate with a race proven multi-position locknut system that is steady and easy to use. It has locking position at every 1/60th of a turn for high precision bearing pre-load adjustments. SmarTubes monocoque construction eliminates the use of fasteners between the snout and tube which saves weight, simplifies assembly and increases the structural integrity of the axle. (Statement applies mostly for Modified Series).