The driveshaft saver addresses the loose tolerance between the driveshaft and bearing found in brake caliper assembly. The shafts are spinning in the bearing race and as a result the shaft is wearing away. The driveshaft saver installs inside the hollow drive shaft and expands the shaft to tighten the tolerance. The device can be installed with the shaft still in the sled. Installation does require use of a torque wrench to seat the device. Recommended starting torque is 40 ft lbs. New longer version shipping after 01-06-2021 requires the flats on the d-saver to be exposed out of shaft on instalation.