Just a friendly bump for DTG advising this bug still exists. Possibly look at this one while doing the Diesel-Electric reworks for CSX:HH ? This bug has been around since the Bright Future patch was released (June '17) This bug only appears for the SD40-2 loco with the YN2 livery. Any other combination of loco/livery has no issue
Just thought I'd bump this old thread as this issue has been fixed alongside the Amtrak switcher DLC release. I tested the SD-40 w/ YN2 livery on a few different services and time of day and no more glitching ! No mention of this issue specifically in the patch notes, the closest to it is: Improved diesel-electric traction engine physics for the CSXGP38-YN2 loco. So this appears to be a stealth fix, FWIW it took 2 years to get this bug fixed. It first reared its ugly head in the Bright Future update (June 2017)...appreciated nonetheless, thanks DTG