Tension Spring for passap Tension Mast: This is the spring that places pressure on the two disks that the yarn flows through on the tension mast. This can be used in any of the tension arms.
If you have cleaned out between the two disks with a q-tip in alcohol and removed any lint and dirt from inside of the tensioning disks and size dial, and the tension is still not what it should be, you still have an option to increase the tension. Take the spring and pull it longer so it is slightly longer than it was. Use caution when doing this. The spring can be pulled a little longer, but not made smaller. A little bit at a time. About 1/4" longer than it was originally usually works. If it still doesn't work, check you reassembled the tension device correctly and that you have the yarn between the shaft of t he tensioner and the "finger" that points into the other disk.