Dewalt Head Spool Trimmer REPL 0.08IN DWO1DT995

My first step would be to take off the spool assembly and see if there is any crap wrapped around the spindle (including behind the spindle plate, see page 12 of the manual). If that doesn't fix it, then I would replace the spool assembly. I had to do this on my DCM571 (the 54/60V trimmer) and I noticed the original spool assembly was model DWO1DT995 and there is a newer replacement DT20656 with a significantly different design that I think works better. If you replace the spool, I recommend getting the DT20656.