Not sure what to think about this.

Normal, if you saw a Legacy or a Lionchief Plus 2.0 and how those axles slide and how that interacts with the idler gears- just imagine when you paid several hundred dollars more. Lionchief Plus 2.0 ET44 as an example on the left of this picture has as much side to side movement as you just were showing if not more. The Lionchief Area51 on the right was just being compared to the plus 2.0 variant to show the different design.

In other words, you are not wrong for questioning it. However, that is "as designed" and assembled and obviously meets gauge spec for spacing of the wheels. Now why on a 4 wheel truck there would need or even be desirable side to side play is an arguable debate and certainly how that changes the mesh and width of tooth contact with the idler gears raises an eyebrow.

I would suggest that the trucks are designed that was to allow some movement for accommodate poor track and some flexibility when going through switches.  It also allows space to get a needle oiler to the axle for lubrication.

I have seen this for many years and have never seen one have problems with the gears.

Happy railroading,

Don

Especially needed on three axle trucks with all wheels flanged.

Many folks have reduced diameter curves so wide side play expands the potential customer base.

In many doubts and questions simply follow the dollar trail.

Agree with all of the above, but you might check the gauge of the wheelsets just to be sure they're correct...which is fundamentally important. 

Thanks to everyone for the input. As I was looking at it last night, I was considering it might be on purpose because of less than perfect track issues. I haven’t really compared this one to anything else. I just don’t remember that much side to side play in anything else.
obx

@obxtrainman,

I have a new (to me) geep, not with Bluetooth though, just command control. Are you planning on putting in a tvs diode for protection?  I haven’t done that before but I want to do that. I’ll need to take a stiff drink first, which isn’t good when you have a 200+ degree soldering iron in your hand.

That’s normal for that engine. You still have plenty of gear mesh. Should be no problem. Just do as others have suggested and check the wheel gauge.

I call the example not OK on my ET44 LC+2.0 just for reference. Same trucks as many recent Legacy engines. Just trying to show recent examples so you have some idea of comparison.

Vernon, I have an engine setup that had the same gear mesh problem. I put spacers on the opposite side of the geared wheel to increase the gear mesh. Worked out great.