Bearing/Bushing noise in 12000?

blue_lak <no_reply@...>

This noise started a few months ago at a very, very low level. I mentioned it when it went for annual service then. Dealer said he lubricated everything and found a couple pins down in the bobbin area, but he couldn't hear anything else. It's getting more obvious and definitely in the upper area according to what I hear with a stethoscope on the housing next to the bobbin winder. I can only hear it at higher speeds, and it definitely has a metallic whine to it. Thoughts on what to say/describe to the dealer when I take it back? I don't want to wait and find out it's a failed bearing and takes other components with it.
Jan in MD

When machine speeds increased, starting with the 10000, there was a substantial increase in the number of bushing failures that would cause the machine to lock up. Due to this they switched to ball bearings, and I'm pretty sure that the 12000 has that type of bearing on the top shaft. My best guess is that the real culprit is the timing belt idler pulley. It's job is to keep the proper amount of tension on the timing belt. Unfortunately the pulley is mounted on a very short shaft on a small metal plate. Over time it tends to bend until the timing belt starts to rub on the plastic clutch ring that engages the bobbin winder. Usually it sounds like a chirping bird, and that may be what you are hearing. It would be in the exact area where you hear the noise. I routinely fixed this problem by bending the shaft so it was straight, but it could also be fixed by just replacing the part. It's easy to access and would not be expensive to repair or replace.

Join to automatically receive all group messages.