I have an Alliant vertical mill manufactured in 1990. I acquired it at the company I worked for in 2002. It has a DRO and a Servo Type 150 power feed on the X-axis. Recently the X-axis lead screw has had a sticking issue. When I move the table to the right all is well, but sometimes, when I reverse the rotation, and move it back to the left, the hand crank 'hangs up' or sticks, and I have to exert extra pressure to move it. It does not take much pressure, but it is aggravating when making fine adjustments, and I fear that this will get worse. It also seems to be a random occurrence. Sometimes I can reverse the rotation on the crank and the table moves to the left without any hesitation. Has anyone ever had this happen with their mill? I would like to hear any suggestions before I tear anything apart.