Use your own dial indicator to measure and correct the spindle tilt.
Using this tool you can rotate the dial indicator against the bed and it will show you how much the spindle is tilted, and in which direction. The distance between the spindle and Dial Indicator(s) is 95mm.
Be sure that your bed is flat before using this tool. This is best achieved by replacing the stock MDF beds with an metal one, and using shims between the bed carriage and bed to level it out. You can use the ZProbe to measure the bed flatness see the guide I wrote.
