I have obtained 4 new run Atlas SD60Ms, all from different sources. The center wheelset in each truck wobbles when the loco is run. Most of the time the center wheelset doesn't touch the rail. Has anyone else had this problem? I have already sent back 2 mechanism and don't want to send any more back if there is a quick fix.
Scott, try holding the engine upside down, and lay a small straight edge along the wheel faces next to the flange and see if there is a slight gap at the center wheel. Sometimes a manufacturer will opt to raise the center wheels to prevent them from riding up over a hump in the track that would cause the front pair of wheels to be raised off the track. Sometimes it can cause the front wheels to climb up over a turnout or sharp curve and derail. There are also some manufacturers who use the center wheels as part of the gear train to power the first and last pair of wheels. The plastic wheel can get worn in the bearing, and make it wobble too.
