Julia, my experience with these clip-in bogies is that fore-aft play is part of the downside of the basic design with some much worse than others. The only way to eliminate it is to use a different bogie design with a fixed central pivot above. That brings with it challenges of a different nature space wise for clearance in front of the pivot point for the worm placement and housing (often it’s where the cab will be). As said I struggled with these issues for years until I just basically threw the towel in and now use the complete Farish bogies as in my latest effort, the class 21.
Bob
Bob
