New Two Truck T Boiler Shay with jerky motion, item no. 25661

[jwerner20@hargray.com]

Just purchased this great looking shay from Trainworld and have just started running it with about 30 minutes on the mechanism.  I noticed a slight jerky motion when at the mid to higher speeds that is almost nu-noticeable at slow speeds.  Researched this issue on line and saw many postings about Bachmann geared engine gear problems in earlier models of the On 30 steam locomotive line-up.  Also noticed the announcement re: free replacement gear sets or repairs of same by Bachmann along the way.  My question is when were these gears improved along the way and how can I tell whether my locomotive has the improved gear sets or not?  I assume this jerky motion does not meet the performance specs of Bachmann and in my experience does not meet my expectations either.  My box is labeled for the Midwest Quarry and Mining Company with an instruction sheet that is numbered S256X-IS001.  The interior of the cab on my locomotive is "green".  Not sure if there are other markings on the locomotive to help identify what manufacturing lots my locomotive came from.  I will be contacting Trainworld re: this issue to see what they think and will consider returning it to them for replacement if they can guarantee via a test run in their store prior to shipping the replacement to me.  If not, I will probably request a full refund.   Please advise on what you think I should do about this issue.  Thanks!

[2foot6]

I would be returning the loco to bachmann for  replacement as it is under warranty.Some locos have had problems but these  are being addressed and hopefully will be OK from now on. Stay with  the On30  scale as it opens a multitude of options for ideas.cheers Peter