Last spring at the ECLSTS I picked up a few “lightly used” Accucraft Fn3 cars art a very good price. I’ve had quite a bit of trouble with them not wanting to track through switches and track work that all my other Accucraft cars get through fine. I finally bad-ordered one of them and got to it yesterday.
I removed the trucks for inspection. I had previously checked and adjusted the back-to back gauge and they were still fine. As far as I can tell the car does not have the problematic wheel profile of early Accucraft cars and it does have the L bracket in place to keep the side-frames from canting.
What I did find was extreme side-to-side play of the axles which allowed the side frames to easily go out of square with the bolster. On closer inspection I found that the journal bearings were very worn allowing lots of play between the axle end and the bushing.
The “correct” fix would have been to replace the bushings, but since I don’t have any in stock, nor do I know if they are even available, I decided on an extreme fix: Modify the side frames to accept USA wheel sets. Before I started I knew the wheel size difference would lower the car a bit and might affect coupler match. I did a comparison of axle centers before I started and decided that the difference was acceptable to me, but YMMV.
The USA wheel axles are too long for the Accucrafrt trucks and the axle end is a smaller diameter than the Accucraft axel. The USA wheel does have a larger diameter shoulder outside the wheel which is a bit larger than the Accucraft axle. To make them fit; both the USA wheel sets and the Accucraft bushings need to be modified. The axles are cut short; I took off about 3/16" by eye with a Dremel cut-off wheel then smoothed the cut. The Journal bushing was drilled out to be just larger than the shoulder of the USA wheel…
The axle ends and bushings are oiled and re-assembled…
The result is little to no side-to-side play…
This fix isn’t for everyone. For starters the over sized USA flange may bother you and/or the change in wheel diameter and resulting overall car height / coupler height could also be a problem for you. Since I run prototypical operations with lots of track switches, reliable tracking is much more important to me than esthetics. As Bart and Bob call it; “Operations Quality” This is the second car I’ve made this change to and may not be the last!
BTW - When drilling out the bushings I found one of them was copper, not brass. I wonder if early Accucraft trucks used copper bushings, or if somewhere along the line a replacement was fashioned by the previous owner?