Tascam 644 capstan bearing and pressure clamp

From the Tascam 644 Portastudio

I have these listed elsewhere on the site, but people search by model number, so I have listed some like this.

Please note, I have seen some of these  where I have taken these out, there should be a Teflon washer here, I have seen this missing or its fallen apart.it goes between the spring and the capstan wheel.

From this unit and maybe others perhaps the 688