MTH Imperial hudson 4-6-4 jumping at 031 switches

A bit more info. The track is MTH realtrax. There are 4 other engines that run just fine. A 2-6-0 from an rtr set, an f3 deisel and a Coors set with whatever that bizzare engie is.

I has the same issue with the Imperial Pacific awhile back.  Check to make sure the screw holding the pickup roller to the bottom of the engine is tight.   Sometimes they work themselves loose and the pickup roller moves side to side and gets caught up on the frog of the switch.

--Greg

Good thought. I checked and it is tight. Next idea welcome.

Are you sure your using the longer drawbar?  If not sometimes it is the tender pulling the engine off in a turn because there is not enough swing room. 

OK now there is something I was unaware of. How long is the "longer" draw bar. That may well be the issue. It was easier to tell if there was a tight wire tether.

I had a derailment problem with an MTH Imperial Northern, although not at my 0-31 switches, mostly going into a curve .  Finally solved it by opening up the tender and giving the wiring bundle that goes to the drawbar a little more slack. 

I don't have the Imperial Hudson, but my K-Line scale Hudson was doing about the same thing on oldschool Lionel 031 switches.

I finally traced it to the drawbar being too short and causing tender binding.

I made a longer drawbar and fastened it to the rear truck instead of the floor of the cab, and the problem was fixed.

Later someone on the forum pointed out that the K-Line Hudson came with two drawbars' the longer one being intended for use with 031. Dummy me, I had neglected to read the manual, or examine what was included with the engine in the box.

Rod

Bob, I believe if you check in the box you will find the longer drawbar, it comes with the engine. It's fairly easy to swap the drawbars. Just be careful it seats properly. MTH has stated that sometimes the tender "screw" is tight or may need a washer put in place. If you call MTH they can give you specific recommendations for your loco. 

Thanks guys. There was no additional drawbar included and the one mounted is marked as a 30mm. I have contacted MTH service and they have pretty much given me the same advise. They told me to open the housing on the tender and loosen the screw holding the drawbar jack and they will be sending me the longer drawbar. I will let you know what size they send and if it cures the issue.

I had to disassemble the bottom of the drawbar mount on the engine to remove a small plastic cover hiding the size markings.

Got an email today and MTH is sending a 50mm replacement for the short 30mm.