Wheel slip does cause damage belive it or not. “Excessive wheelslip can also cause damage to the rods and valve gear as they also carry momentum that must be changed on each stroke, wheelslip will wear down the bearings and on engines built before roller bearings, that's all friction based bearings, which will heat up and damage easily.” -Trainboard.com
@amtrakman4014 for the Big Boy locomotive @Train099 for animating the 4014