The servo motor is a brushless AC servo. Drive is ABB branded. I did the servo setup as per the servo user manual and the values are:

Max current: 17.84
Continuous stall current: 5.55
Voltage constant: 37.6
Winding resistance: 1.24
Winding inductance: 4.14

Servo runs very smooth actually. No vibration, no surging however the only part that is overheating is the output shaft of the rotor. The case remains stone cold. To me, since the case (and the winding in it) is cold so the heating could be because a mechanical problem. However I disassembled checked and I could not find anything bad.

If it is not a mechanical problem then the PC software of the drive has an Auto Tune feature. When I run the test the drive changes the electrical values for the servo (max current, voltage constant etc). So which setting do I need to use? The values from the servo pdf or the values the drive decides?

Thanks