I've noticed a disturbing trend with many of my recent purchases of Williams locomotives. This issue may apply to other brands but my specific experience has been with Williams. I just bought a new, factory sealed A-A set which I promptly disassembled for the project I was planning on using them for. Both gear wells - the part of the motor truck where the gear on the motor engages the gears that turn the wheels - were bone dry. No lube of any kind on any of the gears.
This isn't the first time I've come across this. In fact, the first time I found a locomotive like this I went back through all my Williams fleet and inspected every single one. Not only did I find more like this I even found some examples where one truck was lubed and the other was dry. I guess quality control ain't what it's supposed to be. That's why I immediately checked for this on my last purchase.
Now, every time I have one of my locos on the bench for repair or maintenance I check on this whether it's a Williams or not. Amazing how much better they run (and last!) with everything greased up like it should be.
-RM