Once you get the idea that a typical automotive driveshaft is a series of pieces welded together, repairs to them become fairly simple. While they rarely fail on a car, the story is different on off the road trucks. In this case we lost on on a truck and are reconstructing a replacement out of some salvage pieces. The replacement shaft we located has the right splines and yoke but needs to be shortened, so we put it in the lathe and cut the weld holding the splined end on. Next I took the splined end to another lathe and trued up and cleaned up the contact surface where it mates with the tube.
Finally, we will adjust the length of the tube and bore the tubing to match the splined end, and weld it back on. Usually tubing is pretty thin and the inside diameter matches the slip in ends, but this piece of tubing was obviously selected for heavy service and is much thicker than standard, thus requiring some boring.Once we decided where to cut for the length we wanted we adjusted the position of the steady rest, and cut the tubing with a power hand held band saw. That saves the elbow grease that would be required if using a hand saw. Next we bored the tube as necessary to make the splined end fit in and grooved out for welding. The project now awaits welding. We have paid careful attention to getting the timing right. it will be welded up in the late with one person turning the lathe by hand while the other welds.