Great, amazing how simple some fixes can be, huh?
NP 2626 "Northern Pacific, really terrific"
Northern Pacific Railway Historical Association: http://www.nprha.org/
I fixed the problem. The rear drive shaft had fallen out of the coupler to the motor. It looks like the collar on the motor shaft was pushed too far forward. The drive shaft was barely on it. I moved the collar further back and everything works fine. If anyone else has the same problem with an articulated, that's what I would look for. Thank you for your help.
Do the rear driver move some and then hang up in one spot. If so, reverse back and forth at very low speed and see if you can observe anything physically hanging up where it stops. Maybe an eccentric crank hitting the main or connecting rod, etc. If the drivers are out of quarter, this is a bit tougher to tell if it's enough to cause the problem. Suggest call MTH tech and ask how to troubleshoot a bit to avoid having to send it in.
Paul
Modeling HO with a transition era UP bent
I have an MTH 4-6-6-4 Challenger purchased new 2 years ago. Due to space constraints, I've only run it twice. Maybe 10 minutes total. My problem is the rear drivers appear to be locked up. The front drivers are tying to drag it along. Lights, sound all work fine. Any ideas. Thank you