No one ever said there is a on-size-fits-all lubricant solution and the OP didn’t mention a specific manufacturer and had they mentioned Studer/ReVox, I too would be suggested they sought PGP65.
I’ve seen AMS oils and 105 grease being used by Nak, Pioneer, Teac, Technics owners. I’ve used both products on Sony, Teac and JVC decks without an issue and interestingly, early Teac R2R and cassette decks use sintered capstan bearings. In any event, given Studer/ReVox probably made 0.001% of the entire world cassette deck production, it’s hardly that relevant to this discussion.
Several interesting points to make here:
- You did not say that there is a one-size-fits all lubricant., but by advising specific lubricants without mention of the model you did imply that they were one-size-fits-all. Someone had to add a word of caution.
- You may have seen those lubricants used by the owners of several makes of recorders. But you have not said that they were the right lubes fot these decks, that they were recommended by the manufacturers, that there was not a better replacement for those decks (assuming the original lubes are not still available) or that they did not cause any problem in any of those decks. Personally I've seen people lubricate everything with WD40, and I certainy don't take this as an example to follow - ok, that is an extreme case. Usually the wrong lube will not cause immediately noticeable problems, it will just cause an increased flutter, or intermittent transport malfunctions. You cannot know what the right lube is if you haven't read the service manual. Read the manual before anything else, this is cassette deck servicing 101! - or servicing of anything 101, for that matter.
- It is precisely because the OP did not mention a specific manufacturer, that I replied to check what said manufacturer says in the service manual first. Many manufacturers, not only Revox which is just an example, used many different lubricants in their machines. Besides, how could you be sure it was not a Revox? What would happen if it was? If you were aware of the possible risk as you say, why did you chose to not mention it? Personally I prefer to avoid problems without waiting for the OP to say "oh BTW my deck is a Revox", just because s/he is very probably not aware that this is important information. It is just a matter of being careful. And yes, it is TOTALLY relevant to this discussion.
- Remember that when you reply to a question in a forum, you are replying not just to the OP, but also to all those who will have similar problems, hence the importance of such details - which are not at all details, for that matter.
- Sintered bearings and PDP (not PGP) 65 are completely unrelated subjects. Sintered bearings are designed with all sorts of oils. The fact that early Teac machines and the Studers both used sintered bearings does not at all imply that they used the same oil. They did not, and mixing both oils is a bad idea.
- As Vintage Love said, not many people reply when asked "what lubricant should I use on a cassette deck" without clarifying what type of cassette deck. The reason is precisely that no one can reply to such a general question. This is like asking "what type of oil must I use in my car?" Would you just recommend the oil your mechanic puts in your own car, without consideration of what model one is talking about? It's the exact same thing here. Hence my question to Vintage Love (and the one you should have asked too): what deck model are we talking about? This is the only sensible answer we can give.
This thread is about lubrication, not about replacing the bearings.
