I have an older Kenmore manual machine that I tuned up myself this past winter. Then I have a computerized machine that indicates when it is suppose to go in for cleaning/tune up after so many stitches. The indicator came on last summer so in went the machine. When I got it back the tension was WAY out of wack and it dripped oil underneath, so back it went. I don't feel like it is the same since it came back. It runs ok, but not quite the same. I didn't feel like it needed servicing, but the book says to do it. I'm obsessive about cleaning the bobbin hook area and under the needle plate with every bobbin change. I'll think twice about bringing it in next time if I'm not having a problem with it.