I recently acquired a Singer 401 Slant-O-Matic at auction. When I got it on my bench for testing I found that the motor would not spin. After removing the motor from the machine I found that I could turn the motor shaft with some effort, but it wasn’t able to spin normally.

I removed the brush covers from the motor and found that the motor shaft was seized inside the bottom motor bearing. When turning the motor shaft by hand the motor shaft was spinning the motor bearing itself.

Above is a screen capture showing you what should and should not be moving in the video.

I did put a few drops of kerosene on the motor shaft above the bearing hoping that it would break down the varnished oil that had the two parts stuck together, but even after sitting over night and some aggressive heating with a hair dryer it remained stuck.

Since I knew what the issue was, I didn’t want to waste time pulling the whole motor apart. I unhooked the motor bearing retention spring from it’s mount, and removed the motor brush holders and wires so I could pull the lower motor housing off the motor, leaving everything else pretty much in place.

After removing the lower motor housing, I heated the bearing directly with a hair dryer. I then wrapped the bearing in cloth and used pliers to pull it free from the motor shaft.

Since I had freed the motor bushing from the motor shaft I could assemble the lower motor housing in the correct order.

I dropped the self aligning motor bushing/bearing (that’s why it’s spherical), into the bottom of the motor housing. Then I installed the motor bearing retention spring. I used a wooden dowel to straighten the bearing making it easier to line up the motor shaft later on.

Note: The image above is from a Singer 306K Swing Needle BA3-8 Motor. It’s not the same motor, but the motor bearing retention spring works the same way as it does in the Singer PA9-8 motor. Also note, unlike the BA3-8 motor, the PA9-8 motor does not use any grease wicks to retain lubrication.

Before fitting the lower part of the motor housing all the way back on I fished the brush wires through, and put the plug wires in place. As I put it back together I put the anti rattle spring and electrical isolator in place, then used the two long screws and two long brass nuts to attach the upper and lower housing. I made sure the wires were clear and then turned the motor shaft by hand, It spun freely.

I reinstalled the brush wires and brush holders, and then replaced the brush covers.

I then reinstalled the motor into the machine and tested it out. It works great!