Devil’s advocate…When folks say O-ring to me, it implies some sort of seal. Is there some sort of through-hull fitting, like the tender trucks or cable run, that need to be water-resistant to protect internal electronics? I say this knowing nothing about this locomotive.
Nothing was obvious. I can’t find an exploded parts diagram on Bachmann.
Looking at it, it comes across as a museum piece with lots of attention to detail. The E&P just feels quite fragile, especially the pilot truck. It’s a challenge to flip over without risking something snapping. We will give it a thorough check-up and see how it runs in fair weather and look for places that look like they should be sealed.
(I love that pic - can’t believe we got it back together and working!)
Bachmann mixes up the info and parts on the 4-4-0, the old 2-6-0, and the ‘new’ 2-6-0 (which has a better electronics setup in the tender.) They also mix diagrams on the Product Reference section as well as the Parts section. The Product Reference has 6 diagrams for the 2-6-0 plus the wiring diagrams from the 4-4-0. https://www.bachmanntrains.com/home-usa/references.php
Note that the 2-6-0 and the 4-4-0 are pretty much identical, except for the wheels. So look at the 2-6-0 diagrams.
Bachmann really went to town on the Spectrum 4-4-0 and 2-6-0. They are a bit fragile - I roll them over on to a piece of foam. Upside down you need to support the roof and the stack, as the whistle is not brass and will break, not bend. The tender steps break off, but are available from B’mann Parts.
Being a modeler first and a runner second, I believe I could get it taken care of with just a good visual look at the engine/tender. My suspicion is, it probably doesn’t go on that engine, but also how it is broken (in two) makes my question how it would be broken like that and just a display piece for most. Sometimes O Rings are used like rubber bands and stretched over two post to put tension and hold things together, or as a spacer, not as a seal as most are used for.