The trucks on the cars may be attached a hair too tightly and unable to slightly rock vertically.  Try loosening the screw the barest minimum, maybe 1/16 of a turn and then 1/8 turn if that doesn't work.  Any more than that and truck tightness isn't the problem.

If the trucks can't slightly play vertically, they can begin nitpicking at everything that cars with properly adjusted trucks won't feel at all.  On real railroads, springs take care of that issue, but our little cars are too light for springs on trucks to have any real function, even though model railroad trucks in the Jurassic often had springs.

I've never used JMRI.  It appears to be a convenience to a lot of folks, but it's not something you need.

You need to eliminate your controller as the possible problem source by testing your engine on another layout, if that's possible.  Resetting the decoder to all default values by CV8=8 should get everything to basically function, but the default settings on all these engines usually leaves something to be desired performance-wise, that's another issue for discussion later.

Have you tried F8?

Check the value of CV 128 the master volume.  If it is zero, try sending it at 100.

 I cannot believe that these solutions above are not somewhere in an online manual for the locomotive or the controller, very peculiar

They still offer the consolidation, the pilot part is still the same.  I'm not a businessman which is why I did not retire rich.  But to my simple thinking seems like it wouldn't be that hard to knock out a extra pilots while they're making them for the engines are going to produce anyway.

Replacing a steam locomotive driving wheel is a high precision process, the drivers need to be exactly quartered one side from the other, all exactly the same, or the rods will bind.

https://dccwiki.com/Quartering

Go to this website and see what they have. 

https://nwsl.com/

You will need a quartering jig, but you probably also need a wheel press.  If you don't have any luck with NWSL, try Micro Mark, another well-known Model Railroad tool vendor.  All of these vendors are very friendly and accessible on the phone if you need help.

I don't know what locomotive you're working on or which scale you are in, but you may need to insulate the wheel from the axle. That's something I can't answer but someone else on this forum probably can.

Why are you replacing the wheel? Is something wrong with it?

I have to ask a second question, do you have a quartering jig?

Fortunately, when my friend broke the pilot on his consolidation years ago, the spare pilot was still available.  I put it on for him.  But it looks like now you should cement it back on until you locate the part if you can.

Considering how many of these engines enter the toy market and undergo the abuse that toys undergo, it seems rational that this part should be available all the time. Maybe the Bach Man will stock up again.

Nearly all serious Model Railroaders agree that the smoke produced by smoke units is not realistic at all because you cannot scale the physics of real smoke down to HO scale.  Plus, over time, the microscopic particles carried by the smoke itself will coat everything in the room with a greasy film.

If the purpose of this train is to periodically entertain a child, none of this matters.  But if you're going to run a lot over a long period of time, this should be considered.

The cable's intended use is to allow the power source to be located further back from the terminal track, not to connect a terminal track to another terminal track.

 I have the same thing with two female ends splice together, to allow feeding of power to a remote location where there's a voltage drop. Kind of the southern engineering way to handle the voltage drop instead of a completely organized bus wire system.   Why do a lot of work that you don't have to?😂😂

Maybe one day the Bach Man
will reintroduce the 63" driver 4-6-0, although I'm afraid it's going to have cast on details since it shares the same boiler with the 52 inch driver locomotive which was downgraded like that a few years ago.

I've seen several photographs of Frisco 4-4-0's running in relatively modern times.  Years ago the Bachmann offered what they called the Richmond 4-4-0 .  Two road names came with a centered headlight and although not an exact Frisco engine, it might be a reasonable stand in.  I have two of them that came lettered for the Maine Central and they are great looking and great running engines. I wish they'd come back.

 Both the 4-6-0 mentioned above as well as the Richmond 4-4-0 certainly appear on eBay from time to time.

I'm afraid to count how many times that the Union Pacific big boy has been produced in HO scale, but I would hazard a guess of a dozen or more. 

The last thing we need is another model of a Big Boy, for two reasons:  1.  it's been produced too many times already, and if I'm not mistaken, one of the Bach Man's competitors is getting ready to bring it out again also.  2.  It is way too large to run sensibly on any layout except the largest room-filling or basement-filling layouts.  But when it does come out again, as it surely will from someone, we'll certainly see once again the same innumerable questions we've seen before about why doesn't it run on 18 inch radius tracks on my 4 x 8 layout?

I'm hopeful that the Bach Man continues his very sensible course of offering smaller and midsize locomotives in a Model Railroad world where virtually no one else does.  I have a lot of locomotives, but a large majority of them are Bachmann products because they are sensibly sized for my moderate layout.  All you have to do is check the competition and see that nearly all they offer are huge mama-jamas that need 36 inch radius curves or more to function properly and even look right in operation.

I have a semi outdoor small layout in a covered space out of the rain but open to outside air.  I had been building it for the last three years using EZ  track left over from a previous project, but one by one electrical conductivity failed in nearly all the rail joiners and switch pivot points.  Some of the joints were soldered and restored, but everything I did was basically sequential Band-Aids trying to keep a corpse alive and trying to keep ahead of the failures.  So I demolished it all in the last couple of months and started over.

This is no rap on EZ track, anything I would've used out there would've eventually failed.  So I'm starting over but this time I'm using Kato Unitrak mostly because of the appearance of Code 83 rail.

The difference is that at this point in time, we know we're leaving this house within a year or two.  So I'm not fastening track down to the layout surface at all, but rather making removable scenery sections that bump right up to the track to hide the fact that it's a plastic roadbed sitting on a table top.  The track is spray-painted brown and it really looks OK when you hide most of the road bed. I like the reduced roadbed height since I am a branch line.   It's all removable and I can take the track with me when I go, which is a substantial investment of several hundred dollars.  I'll be able to use it again on the next layout wherever the next house is going to be.

This is one place where I would never even thought of handlaying track.  The outdoor layout has always been a challenge. It's the only place I had.  People with basement layouts have no idea how good they have it.  Down here on the Gulf Coast we don't even know what a basement is.  Or snow 😂😂😂.

The best thing about hand laid track is that you can use very light rail with irregularly spaced and staggered ties like on shortlines.  I promised myself that on my next layout I'm going to hand lay at least some yard siding or something right in the foreground.

But, I would think that hand laid track is really only worth it where it's really closely visible, and that you're wasting your time doing it in spaces at the back of the layout or up in tunnels or somewhere.

I did not know about Accumate N scale knuckle couplers.  I had known of accumate couplers being provided with Accurail HO scale kits, but that was it.

I had thought about building a limited N scale freight train roster with steam locomotive to bring to other layouts to run, but when I begin to understand the coupler inconsistencies, I let it go, I just didn't want to fool with all that at this point in time.

There's nothing dangerous about a locomotive trying to pull more cars than it can.  It will spin its wheels if it's too light, or stall if it's very heavy.