Lionel Polar Express DOA???

Check the traction tires, one may not be on correctly.

@James Ford posted:

I just got a brand new lionel polar express Bluetooth ready to run set and for some reason the engine seems to wobble back-and-forth on straight track, I’ll try to embed a video. Wanted to see if this is normal for this engine or if I should send this back. It is not much movement but you can hear an audible click with each revolution, I don’t mind it much but don’t want it to turn into a mechanical failure either.

James,

   After you check the traction tires as GRJ suggests you can try doing the following. It looks like your tracks are laying on a rug. The best way to run O gauge trains is on a hard surface such as a ply wood board. You can also secure the track with screws which will help the smooth running of the train. On a rug the rocking of a train is the natural result of the side rod action. Also try slowing the locomotive  down it will rock more the faster it goes. One more thing DOA or Dead On Arrival is used only when a locomotive will not move, yours looks to be very much a live.

   Good luck

JohnB

Attached are some pics of the traction tires and the bottom of the Loco along with some videos of it running at slower speeds.    I’m wondering if I added additional rubber traction rings to the front tires if it would help.

@JohnB posted:

James,

   After you check the traction tires as GRJ suggests you can try doing the following. It looks like your tracks are laying on a rug. The best way to run O gauge trains is on a hard surface such as a ply wood board. You can also secure the track with screws which will help the smooth running of the train. On a rug the rocking of a train is the natural result of the side rod action. Also try slowing the locomotive  down it will rock more the faster it goes. One more thing DOA or Dead On Arrival is used only when a locomotive will not move, yours looks to be very much a live.

   Good luck

JohnB

LOL, yes, the DOA was mean't to grab attention and get others to chime in I've had a few MTH steam engines which are of a higher quality then the polar express so I wasn't quite sure if this behavior is to be expected of the lower quality engine or if this is something else. I've scoured the internet looking at videos others have taken and it seems hit or miss, some of them don't seem to have any sideways wobble, and others do show a sideways wobble. I'm going to try and replace the traction rings on the back and add two additional rings on the front to see if it helps.

@James Ford posted:

I'm going to try and replace the traction rings on the back and add two additional rings on the front to see if it helps.

The front drivers will NOT take a traction tire.  It has no groove to seat them in. 

Marty is, of course, correct.  Stick with the two traction tires you have.  Also, instead of replacing them, simply by using a small flat bladed screwdriver, you can coax them back into the groove properly, that will likely address your wobble issue.  No reason to replace them as you have to get the new ones on properly anyway!

Since it appears that you are running on a flat loop with no elevation changes or inclines, if the above does not work out to your satisfaction, you could always try removing both traction tires entirely and see if that helps.

No traction tires can also cause a wobble as the grooves in the wheels jump around.  That's not really the best solution to the issue.

Agreed, but it may be worth a shot if none of the other suggestions solve the problem. The OP has nothing to lose except some time and effort.

Even a blind squirrel sometimes finds a nut

James, check those tires! My LionChief Plus 2.0 had a severe wobble before with old tires. I replaced the tires this morning and a huge difference as the wobble is mostly gone. here's some video before and after on service rollers and then on track.

I got to tell you though, Lionel needs to replace their tooling for the driveline on these semi scale Berkshires. My worn out 2007 Polar Express Berkshire that came with the set back then, has a much tighter driveline than my LionChief from 2019 shown in the video below. James, is your driveline this loose?

I have a PE that had either a bent driver or axel on the rear set. Replaced it and the wobble went away.

@WesternPacific2217 Really appreciate the detailed information and yes the drivetrain is pretty sloppy, I'll get a video of it after I replace the traction tires and see if there are any other adjustments I can make.

I think I figured out the issue but now I need to figure out a solution. After removing the nuts on the rear tires I check to see if the other tires with spin freely and noticed binding. It seems that the armature on the drive train comes in contact with itself during a revolution creating a slight binding that requires additional force to overcome and when this happens the drive train shifts from left to right creating the wobble see the video and picture attached below. The real question is there an easy way I just this before I end up bending something and making it worse.

https://youtube.com/shorts/vX1eh_Wsuas?feature=share

After removing the wheel nuts from the front tires the armature moves freely without the binding but I would like to fix this and restore it to the way it supposed to operate

Time to check to see if that rod screw is tight and also measure the gauge of the wheelset, see if that set of wheels is gauged farther apart than the other drivers.

Also, the cylinder and rods may be bent slightly inward.

Finally, check and see if this screw is loose and allowing the slide guide to move around.

@James Ford posted:

I think I figured out the issue but now I need to figure out a solution. After removing the nuts on the rear tires I check to see if the other tires with spin freely and noticed binding. It seems that the armature on the drive train comes in contact with itself during a revolution creating a slight binding that requires additional force to overcome and when this happens the drive train shifts from left to right creating the wobble see the video and picture attached below. The real question is there an easy way I just this before I end up bending something and making it worse.

James, first your driveline looks really dry, I recommend you lubricate it with Lionel oil or something equivalent. Second, that shouldered bolt, if you can call it that, doesn't look like it's screwed in all the way, or the shoulder is too long. your main rods are even sloppier than the main rods on my PE loco! :-( Make sure those cylinder slides are lubed and tight. They can be adjusted by gently prying them, I had to do this on my PE loco as well. I hope one of these solutions works!

Some else just mentioned running the loco inverted with power to see what is going on, video below, really able to see much more from this vantage point.

@WesternPacific2217 the bolts don't allow you to tighten all the way down, they are thread-less near the bolt head I'm guessing to prevent over tightening and to ensure there is play in the linkage. If you have time, take a look at my video and let me know your thoughts.

I took @gunrunnerjohn suggestion and did find a loose screw on the piston but it did not help after tightening it up.

https://youtu.be/jeNDHV0Y-sM

@WesternPacific2217 what type of rollers are those you are using for testing, I need to get some of these. I saw some others mention JAK rollers but can't seem to find these online any more.

James, I got my test rollers from MicroMark. The rollers are on special for $41.95

https://www.micromark.com/O-Ga...s-Assembled-Set-of-4

The non threaded part of the bolt is sometimes referred to as shoulder. That last video looks pretty good, I don't see any interference upside down anyway. You still might need to adjust the slide rod.

If the rod screw is all the way tight then remove it and file the head down to get the clearance needed.

You shouldn't have to file the head of the rod bolt down to make these work, I have worked on a lot of them, and that's never been necessary.  The piston rod guide may be bent slightly toward the wheels and allowing the bolt head to hit it.

I'm with John on the filing, don't. The driveline parts are plated and if you take a file to them the plating will be ruined. All the driveline parts should be able to adjust via some gentle tweaking.