I think you may be right about the chassis swap, I've tried but I think mine is shot. ANd yes I do love my Gen 2. It was the second trainset I ever got as a kid and she's joining my garden railroad roster as my #2 hauler so a lot of shell modification work is underway, just needed to figure out the mechanical issues. And that thread is really detailed, bookmarking that for future reference, Thanks so much for your help and Input~!

So before I get into the issue, yes i have been searching and found a lot of information just not on my specific problem. I am well aware of the generation 2 issues with the gearboxes. However my gear box is not "broken" nor are the gears stripped. My issue comes from the motor running and the gears not engaging. Now I did open up and find ou the issue. My back driver wheels keep fall off the axles ever so slightly even on the rails and the gears can no longer engage each other. Does anyone have a proper fix for this issue or has dealt with this specific issue or should I just try to swap onto a Generation 5 chassis?

Manythanksin advance.