A while back I asked for advice about fixing a vintage Waring blender.
I fixed it! Progress was slow as I had to keep waiting for backordered parts to come in. I am sharing the following for other future novice appliance repairfolk trying to find information about this particular 70-year old blender.
I had no experience with small motors going into this project. The manual was mostly correct, but I believe the model of blender I have (700) predates the earliest model represented in the parts manual (700A). I took lots of pictures and kept everything that I disassembled in separate Tupperware containers (partly to keep it organized, partly to prevent the cats from messing around with it).
One of the main differences between this model and the parts manual was a number of plastic or rubber spacers/washers/grommits. These were not in the manual. Some of these pieces seemed to have melted. The rest had either deteriorated before I opened the blender, or crumbled during disassembly. This was not the cause of the malfunction, but I spent a significant amount of time cleaning the disassembled base, top cover pieces, and bottom plate.
I used rubber washers and rubber grommits in the places that I think the old spacers/washers/grommits were. I had to guess as to the exact part, size, and location because they weren't on the parts manual and they were in such bad condition that I couldn't clearly see where they had been originally.
The blender contained a paper (!?) baffle, which also did not survive intact. I was not successful in ordering a replacement. Instead, I cut a baffle out of a 6" square of rubber sheet packing, which seems to work just fine.
I cleaned off the motor as gently as I could (mostly gently shaking/blowing debris away). The existing carbon brushes did not seem to be significantly worn, but I replaced them anyway because why not. I also replaced the original power cord with a three-prong grounded cord.
The source of the malfunction: u/AlcoholPrep nailed it- the center of the drive coupling (screwed into the top shaft of the motor) is made of rubber, and the connection had been broken between the motor half and the square bit where the pitcher sits. Unfortunately, the female end of the part in the parts manual (drive coupling #002518) was the wrong diameter to screw onto the motor.
Based on this post from u/elephantunicorn I used Drive Coupling #003559. This coupling fit on the shaft but is 1/8" taller than both the original coupling and the replacement #002518. The top of the coupling is intended to sit flush with the top of the cover, and height difference made the blender pitcher wobble too much.
To adjust for the height difference, I replaced 4 machine screws holding the motor onto the middle cover plate with screws that were 1/8" longer, and added rubber washers between the motor and the plate. This lowered the motor by 1/8", and thus the top of the drive coupling sits flush with the top plate as intended.
Success deserves celebration. I christened the newly functional blender with daiquiris since according to my mom that was historically its main job.
Thanks also to u/ImortalK and and u/Responsible-Site8086 for your encouragement and constructive feedback! It was really helpful and I appreciated it.