Is teflon based lubricating spray bad for tonearm bearings?

What's the manufacturer's recommendation?

It's a 35 y.o. Linn Ittok LV-II and I don't recall anything about tonearm lubrication in the manual.

But Linn is still in business, so you can still ask.

IIRC, it is not rust, it is probably a tensioning issue. Probably.

Search the web on the subject of Ittok bearing issues, on some their older arms.

eg, pretty near 100% of all old Dual turntables need their arm bearings re-tensioned. They even mention it, as a maintenance procedure in many/some the tech manuals for the given tables.

It is sometimes due to machining of components and the resulting release of tension in them, over time.

I think, IIRC, that this plagued the orignal lower priced syrinx tonearms (many years back). That it happened far too soon in their lifespan.

Eg, Depending on the nature of the metals in question, this vertical bearing (vertical motion, horizontal bearing pair) bearing will either loosen or tighten too much, over time. Probably 10 - but closer to 15 years down the road.