So we've got this beautiful layout that we've been working on, and mostly everything works great.
We've run lots of modern diesel, steam across almost every inch of track, as well as some older PW equipment like my 1666 steam (which also has a 2 wheel pilot)
For whatever reason, we can't get dad's old 726 to travel straight across the Ross 22 degree crossing in one direction. It seems that, since the appraisal from that direction is in a curve (54 inch), the pilot remains pointed in the direction of the curve as it enters the crossover, and with the rear of the loco still in the curve just long enough, the pilot steers itself onto the wrong direction of the crossover right after the diamond.
Has anyone installed a really light centering spring similar to those used on couplers to gently coax the pilot to a straighter path? The 1666 has no issues, and I've checked the condition of the pilot on the 726. Everything seems good, including the light spring that keeps gentle downward pressure on the unit. No snags, and it's lightly greased where the pilot pin slides across the bottom of the chassis.
Thanks for any advice!