I have a Little Gracie II frame with a Juki TL 98 Q. I bought it used 3 years ago. I've made quite a few quilts with it. In the last couple of years I've replaced the plastic tracks twice. Although, I don't see any cracks in the plastic the carriage does not glide smoothly in a certain place. Which causes problems as I quilt. Does anyone else have this problem? Can you replace the plastic track with something else? Like metal? Or would that be loud and cause more problems since the wheels on the carriage are metal? Is it that I tighten the quilt top too tightly on the rail? I can't seem to figure this out. Frustrating!