Lubricating train axles - which oil to use?
Generally for this sort of thing the recommendation is a &quot;light machine oil&quot; (the wording from the Hornby Maintenance sheets). These are &quot;non-penetrating&quot; and so won't damage the plastics which might happen with 3-in-1 or WD-40 style oils.
This can often be found as &quot;Sewing Machine Oil&quot;.
Fleischmann (a model railway brand) sell their own &quot;Special Lubricating Oil&quot; (FM6599) for use on their and other trains, that is usually widely available, but is probably somewhat more expensive than a general purpose machine oil.