Originally Posted by ghostrider
Pulling it backwards is supposed to leave lint in the tension disks, but I've been doing it for over 20 years on my Viking with no problems at all and none on the newer Bernina either. I clean between the discs whenever I clean the bobbin area, no big deal. It's just lint, not a tension issue.
ETA: Definitely raise the foot first. (do people really unthread with the foot down?)
If your thread is so linty it leaves lint in the tension disks when you pull it thru backwards with the tension disks open it's probably too linty to be using forward!!
The only machines I know of that you really, really shouldn't pull the thread out backwards are sergers and it's not because of lint in the tension disks. It's because they can be very hard to get threaded in the right order. And if a serger isn't threaded in the exact right order it will not sew.