Was cutting some limbs and the blade started slipping. Will somewhat turn under power without a load on it. Stops turning when a load is applied. I removed the head, placed pliers on the shaft of the cutting head and it wont turn, so I’m guessing the head is not the issue. I was going to remove shaft assembly from the power head to check the clutch/springs, but i figured I’d check with the experts first. If memory serves me, i had this issues a couple years back. Can’t remember the issue, but I think it was the spline shaft?Any ideas? Thanks for the help.