Does the Jetspin use the plastic spinner? I would assume it does due to the date of manufacture.
If it is the plastic one, honestly they just suck. Gottlieb's previous metal spinner was pretty good. But nothing like the William's and Bally spinners, they are a great design.
No lube is required on spinner assemblies. The guide holes in the support bracket for the spinner should be clean and not binding or interfering with anything on the spinner assemly. Make sure the switch adjustment is correct for the spinner leaf blades under the playfield.
There is nothing to lubricate on a spinner assembly.