Originally Posted by EvieRaven

I wanted to add some more info to this old post because I never really came back to it. I also had a DM that I missed.

I ended up joining a Facebook group for vintage Japanese sewing machines, and I found a couple helpful posts from others. One was an old post (4 years ago) from someone who had a similar looking machine with the same broken part. They replaced theirs with a brass gear. One person with the exact same machine who was able to take photos inside the top of theirs which confirmed I did in fact have a completely broken/missing plastic gear. I ended up saving some photos from those posts (attached).

Someone in the comments of the older post gave a part number, but I don't know for a fact that it is the part that the op ended up using. However because it was all I could find, that part number was #3692-169S. This part is for listed online as for Kenmore 158 machines, but the JA 58 number I found on my machine (below) is also used on some Kenmores?

Most of the places I looked for this part online said it was sold out or no longer available, but I did find one store that still had it listed, and I attempted to buy it. After about a month of no contact and no part in the mail, I got a refund through PayPal.

That's where my energy for this project started to dry up. I also started to worry about taking my machine that far apart, even though I *should* be able to do it. I know it does do a nice straight stitch right now and I don't want to mess that up.

However having some time off for the holidays I decided to give this another look. I started looking up sources for parts again. I ended up buying a part off eBay that may or may not be correct. I will try to remember to update when I actually make some more progress.

The JA number on the bottom of my machine is JA-58 80670 I thought this might be helpful info.