g-scale engines run shakey at times-update

[tiger88mm]

thank you to every one who responded to my dilemma of my Bachmann engines not running right,3 of 4 engines are running strong and pulling there loads in all there glory,unfortunately the Heisler is down due to a split gear on one of the drive axles,pretty much all info was addressed  and engines were still giving me problems,so whats the ole motto,if all else fails  look at the owners manual,and one area that I must have over looked was to put conductive lubricant on the drive wheels-bingo-they're running now  2 days strong,again thank you everyone who responded and helped me out
Bryan