I had a moment of insanity. I figured, since I was already planning on the sewing machine going into the shop, I could at least satisfy one curiosity I've always had.
Here's what my sewing machine looks like when I take the bobbin case out.
Usually after every bobbin of thread used, I'll dab a q-tip around to pick up any obvious lint and fluff hanging around.
Every two bobbins, I try to open up the area and give it a real good cleaning. The little tab on the left of the wide silver "U" in the above picture opens up the hook removal.
Now you can see the spot of my deep curiosity. What's beyond that silver screw in the center? I envisioned gears and springs and a whole lot of lint. And hey, if I'm gonna be taking my machine into the shop anyhow, why not take a peek?
But before I actually unscrewed it, I decided I better take pictures of my needle positions, cuz this stuff isn't covered in the owner's manual! :D
Little do I know, this picture is what saved me a lot of trouble.
Undid the screw... and hey, I was right about the gears. But no springs or other loose stuff back there.
In fact, not even a lot of lint. No pools of oil either, so I haven't been over-oiling my machine.
Here's the back of the piece I unscrewed out. Just a simple gear to match the bar of teeth above.
Curiosity satisfied! Now to put my machine back together. That's when I had a second of panic - how do I know which gear teeth match up?! I tried to eyeball it, but I was one gear off. Referred to the picture of the needle all the way down, and was able to get it back in place. Phew. ;)
The crazy thing? My free-motion tension is ok now. I tested it long and hard. No more tear-inducing tension problems. I'm not sure if I need to take it to the shop now. Gonna have to sew for a few days to get a better idea. Cuz I'd rather not spend that kind of money if I can help it.
Just don't hold me responsible if you try this yourself! :)