Hey all,
I recently purchased a Juki 1508 NH (my first industrial machine!) and have been making some minor repairs and upgrades over the last couple of weeks before I put this workhorse to work. There is really only one last issue I am dealing with. That is whenever I use the knee lift, there is a low pitch squeak that comes from somewhere in the head unit (I'm thinking it's maybe the triangular link in front or possibly from the bushing/rod/spring on the presser foot rod, though not positive). If I use the back lift there is no sound (it's very smooth) and if I leave the back lift up and engage the knee lift there is no sound (ruling out the arm itself). It's only when it has the additional tension of being completely engaged using the knee lift that it makes the sound. I also noticed that if I put a little lateral pressure on the knee lift when engaging it the squeak is louder making me think something may be slightly out of alignment.
I know it maybe impossible to know exactly what the issue maybe just from a description, but I'm basically looking for advice on first steps to diagnose where exactly it's coming from. Should I just break down the entire head assembly while testing each time I take off a component. Then clean with alcohol, relube, and reassemble? How would y'all go about it?
Another related question is that the previous owner seemed to put a thick grease around the springs of the presser foot rod. I've never really seen grease used for these areas and thought this might be a no no. Should I remove that? (You can see it in the photo)
Thanks!
