After seeing this thread and the fact that the Legacy Mohawks might have a problem I took a look at mine. I think you can cross that one off the list as mine appears to have a spacer next to the gear. It begs the question were they all supposed to get a spacer???
They cheesed out on the drive gear though. Rather than pressing the worm on a smooth shaft with bearings on the smooth shaft they simply machined down the teeth to fit the bearing. Come on Lionel!!
Pete