This Walkman has had its belt replaced with the correct specification belt, the capstan bearing has been oiled with high grade watch oil, the head and pinch roller have been cleaned with IPA and rewind and fast forward are actually as silent, if not more silent, than my other budget Walkmans. Despite all that and even without a tape in, the play mechanism has a regular 'knocking' noise which sounds a lot like an old steam train... Endearing, but a bit worrying and very noticeable for music with lots of quiet parts. This knocking does not occur with FF and rew, so I'm not sure if it's even likely that the belt is the culprit or if anything is blocking the belt path... I've been racking my brain to try and figure out how this could be the case, the music itself sounds perfect and crisp but the mechanism is just quiet loud compared to ff and rew.
Thanks for the move. Anyhow this was fixed... Just sprayed white lithium grease on the gears and then left the Walkman to play for a few hours as to not let the grease gel up. It's all working fine now, for a bit the W+F was a bit nuts but it seems to have settled down after readjusting the pot and a bit of cleaning. May need to clean it again as one tape is having a bit of a squeaking problem (others are not) and I suspect there may be some resistance within the unit. Besides that everything is fine again!
UPDATE: Seems to have developed a fault after a day or two of working fine. While the knocking disappeared I did notice a squeaking when playing a certain type 1 tape I have. Well now when I press play the mechanism seems to click like crazy if I hold the button down or play just disengages after a second. FF and rewind don't but this is also because those mechanisms engage a different set of gears I believe. Any ideas how to sort this out? I'm thinking right now that a deep clean is in order, think I went completely overboard with lithium grease and in the future I will only apply minimal amounts where necessary.