On 19/03/2017 2:54 PM, DoN. Nichols wrote:

If the step belt pulleys version -- I don't know, but perhaps
the spline which couples the upper pulley to the spindle is dry and
worn.

If the bearings in the front pulley are worn, belt tension can pull the
face coupling out of alignment. This will cause a knocking sound in
direct drive, that will go away in back gear. Had a Millport with this
problem.

Jon

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus