I have two identical Shays. One runs nice & quiet, the other has what sounds like a gear noise. The sound changes as the speed changes. Can I use a drop of LaBelle oil on the Rods? I run HO.
I guess I’m confused. What rods? Your picture shows a Shay, but there are no side rods like a regular steam engine.
You said it sounds like a gear noise. I would check the gear case where the motor is reduced and transferred to drive shafts or the line shafts. It depends on the type of drive used whether power goes through center drive shafts or through the line shafts. Roundhouse and Keystone Shays used separate drive shafts; other makes generally gear to the engine crankshaft and power through the line shafts.
Fred W