New MTH Imperial Cab Forward

you need to add another roller to the tender and your problem will go away add 2 rollers front n rear of tender would be the best option. you can install the rollers or have an asc tech do it for you!

Alan

Great idea Alan!

Is one of the tender leads "hot" so I don't have to add additional wire connections from the tender?

yes the center roller on the train engine or tender from the ac transformer feeding the tender, then the pc board changes the ac to dc to run the electronics inside the tender dc actually runs the can motors in the engines mth or Lionel ! if your adding a new roller then you ill have to run  new wires from the wires which is already connected to the engine roller electrically they are at the same potential AC ! you would only have to add one wire from the engine roller already on the engine or if there is a roller already on the tender add wire to the existing  roller and then attach new wire form originally roller to new added roller. your actually just adding another roller and wire. all the rollers are all connected together to the same wire which is the center rail wire!

Alan

Thanks Alan! I can tell you are an MTH Tech School graduate!

FWIW, the parts to add a roller to the tender should still be available from MTH if the mounting hole is present in the tender. 

OTOH, if the trucks are like the earlier RK Cab Forward, you'll have to ad-lib, here's a couple of examples I've done in the past.  I use Styrene or fiberglass to build the mount and then either use existing hardware or drill & tap for screws to mount the roller assembly.  The roller I normally use for these upgrades is the MTH BD-0000042.

Also, I recommend adding a PTC in the tender roller line to protect against derailments.  The small wire in the tether can be cooked if the locomotive or the tender derails and a roller lands on an outside rail.  The RXEF090 is a suitable part, and it will protect against wire damage from a derailment.