Lionchief A5 vibration when running forward

Also, requarding warranty- I have heard that the one year warranty when purchased from an authorized dealer is void if the item is over 3 years old. My manual has a date of 3/16. Does that mean this loco is 6 years old and out of warranty?

The motor could be loose in its mount. It could be pushing itself up out of the gearbox a bit causing the issue.

In reverse, the worm may be drawing the motor back down where it should be.

Some locomotives have a motor mount screw recessed into the bottom. Of the chassis, checking its tightness is a place to start. Sometimes this screw is loose or missing from the factory.

However,  I'm not aware if the lionchief A5 has the design. You may have to open the shell to check if the motor is secure.

@Rob W. posted:

Also, requarding warranty- I have heard that the one year warranty when purchased from an authorized dealer is void if the item is over 3 years old. My manual has a date of 3/16. Does that mean this loco is 6 years old and out of warranty?

Yes. Warranty is for one year from the date of purchase as long as the loco is purchased within 3 years from the date of manufacture.

@RickO posted:

The motor could be loose in its mount. It could be pushing itself up out of the gearbox a bit causing the issue.

In reverse, the worm may be drawing the motor back down where it should be.

Some locomotives have a motor mount screw recessed into the bottom. Of the chassis, checking its tightness is a place to start. Sometimes this screw is loose or missing from the factory.

However,  I'm not aware if the lionchief A5 has the design. You may have to open the shell to check if the motor is secure.

I tried pushing down to stall it and see if anything was slipping, and the motor stalled with the drive so I think it's meshing ok and staying in place. I did discover that by lifting up on the bottom of the cab roof overhang, and bouncing it a bit I could duplicate what is happening. It's pivoting front to back, like a bucking bronco. So when it is running in reverse, like you say, the worm is drawing the shaft up and keeping it in place. When it is running forward, it's fighting itself as the shaft bounces up and down. What I don't know is if the motor is bad, or if the control board is making it behave that way. I'm going to keep running it and see if it continues to get worse. If that's the case then I guess I could say with a fair amount of confidence that the motor is the culprit.

A video would be useful if possible.

@PRRick posted:

A video would be useful if possible.

I took a quick video but it doesn't really come through. You can see the bell wobbling and the cab kind of bounces about midway through the video. I don't know, maybe my expectations are just a little too high. It does creep super slow, and as long as I skip the speed steps that really bother me, it runs ok. Still, for the price I payed I was expecting a little better than just "ok".

Can you see the flywheel while the loco is moving? If the flywheel is bouncing in and out, it could be a bad motor.

Can the motor be wiggled by hand in relation to the chassis? I would look for a loose motor mount.

Are you comfortable using hand tools?

So, despite the lack of documentation and the fact that I can't find a parts diagram or any post where someone has opened one of these up and examined it, I went ahead and removed the boiler. Four screws hold it on, two in the large air tanks under the cab and two inside the cylinders. Now that I can take a better look at things, I spun the motor by hand and I can say that my first suspicion that the motor is very "coggy" as it turns was correct. Seems like a fairly high torque motor, which no doubt helps with the steady low speeds. There is practically zero play in the motor shaft. I paid careful attention to the flywheel as it ran, I didn't see any indication that it was wobbling or out of round. The mechanism without the boiler on is pretty light, any vibration is minimally noticeable when running by itself. The boiler adds a ton of weight up high, making it top heavy, which exacerbates the problem. The motor doesn't cog as bad in reverse, so its less noticeable. I'm just going to keep running it, maybe at some point the motor will break in and turn a little smoother.

A motor with strong magnetic "cogging" will cause the effect you see, it may just be a bad choice of motor by Lionel for this model.

Sorry to resurrect an old thread, but @Rob W. any update on the vibration / stuttering of your LionChief Plus A5 0-4-0?

I know EXACTLY what you're referring to, because I've seen it myself with two different Legacy 4-4-2 Atlantics (6-11225 and 6-11117.)  I actually bought a replacement motor for my 11225, but never got around to installing it, because that loco is jammed with electronics.  The wires have very little slack / clearance, and you can't remove the motor without removing a bunch of circuit boards first.  I strongly prefer the way MTH did things back in the PS1 days: most, if not all the electronics were in the tender where they belong!

The Atlantics have a very low gear ratio, I believe about 30:1 or even 36:1, and their worm drive is self-locking.  That low of a gear ratio might challenge the reaction time of the speed control system.  I think at the problem speed steps there is a vicious feedback cycle.  For example: the motor is commanded to turn faster.  But the speed of the moving train causes the teeth of the worm wheel on the driving axle to lash against the single-thread worm.  The friction from tooth contact slows the loco briefly, so the electronics command another speed increase.  This slowing and surging cycle repeats as long as the loco remains within that speed range.  Even in locos without speed control, I've heard of self-locking worm gears causing "bucking" on downhill slopes.  New LionChief 2.0 Pacifics and Hudsons have an idler gear setup with a back-driveable, multi-threaded worm.  This is a definitive way to address bucking and surging, but the gear ratio is much taller, i.e., 17.5 to 1.

We could also be seeing a gear mesh issue.  Neither your A5 nor my troublesome Atlantics have a true "gearbox."  The worm gear is pressed onto the motor shaft, and it's only supported on one end by the lower motor bearing.  Thus the motor itself has to absorb any thrust load.  I thought about trying to alter the gear mesh a few thousandths by shimming the motor mount.  But the motor mount is angled, so I would be adjusting the fore-aft position of the worm at the same time as its height.  And all of that wiring discourages me from even trying!

Thanks for sharing last year, great video too!  Perhaps some others will chime in with their experience and recommendations.

I have the 6-84945 PRSL Atlantic, and I've seen nothing like this issue.  I am curious about the comment about the gear ratio, I'd think the 30:1 gear ratio would be less likely to cause cruise control feedback issues.  My PRSL Atlantic exhibits some of the "Atlantic waddle" that most short wheelbase locomotives seem to have, but no bucking for-and aft like is described here.

FWIW, I've see the bucking for-and-aft when the motor has excessive end play, that's what I'd be checking.

There is a possibility, (slim, if the drivers have been apart/not assembled properly), that the drive train is out-of -quarter.  The two axles and linkage have to be assembled properly. 

Wow, can't believe this was a year ago! I've expanded my roster a lot since then, but I was kind of obsessed with this little guy because at the time I think I only had two locomotives. I'm happy to report that the vibration has settled down quite a bit with extended running. It is still noticeable when running light, but when loaded down with five freight cars or so it is almost imperceptible. I do think the motor has improved with some break-in time.