Reply by Chris

A Trick a machinist friend taught me when I had this happen on my Old DP:
1. Clean as Charlie said
2. Open the Jaws fully
3. place in Freezer for a couple of Hours (Metal Contracts)
4. Re-insert as suggested by Charlie.

When the metal heats back to room temp the mating surfaces will fit far tighter. It worked for me….

-- "Everything that is great and inspiring is created by the individual who labors in freedom" -- Albert Einstein