Sir:

I bought a new Class J in Jan.  It came from Trainworld.  It looks fabulous.  The headlight comes on bright at a very low throttle setting which is nice.  The tender looks great and the back up light works great.  It pulls more than anything else in N scale including my 2-8-8-2.   However, it had one bad problem.  It "jumps" It stops or hesitates depending on speed, each half turn of the drivers.  I sent it back and Trainworld promptly sent a new one.  It did the exact same thing.  I sent it to Bachmann and they too two monts to get it back to me.  The paperwork said they reaplaced it.  This one has the same problem the first two did.  It hesitates every half revolution.  I have run it and run it forwards and backwards at all speeds.  I've had it for three days.  Now it does run acceptable in reverse, but still hesitates in forward.  There is a noticable change in pitch of the gear whine with hesitations.  At about 35 mph it runs with only a little "bumping" and at higher speeds it isn't noticable.  At speeds below about 30 it jumps more pronounced as the speed is decreased until about creep where my MRC throttle makes it fairly smooth.  It seems a little better than when I first started running it. 

Do you believe it will straighten out with use?   Reverse it OK now, but not perfect, and forward is not very good. 

Thanks,
ClassJ