Truck Replacement On A Walthers Mainline SD50

I was running D&RGW 5510, a Walthers Mainline SD50, as lead loco in a consist. I ran it up to a switch that was set against it, stopped to throw the switch, got distracted, and left the train in place for some period of time. The problem was that the lead truck ran past the insulated joint that isolated the powered frog, which caused a short, but the short wasn't enough to trip the circuit breaker on the command station, so instead, the loco sat there long enough to heat up the wheels and melt the gears in the truck.

When I finally threw the switch and tried to run the train again, the locos behind 5510 in the consist could push it along, and in fact the rear truck on 5510 was providing power, but I realized something was wrong. At first I thought 5510 might have been dropped from the consist, but I could also see the front truck was derailing. Picking the loco up, I realized the front truck was seized and the wheels were out of line. At that point, I thought of what I'd heard now and then about shorts at switches that don't trip the circuit breaker melting gears.

It's a little hard to see, but the wheels are out of level and out of gauge. None of them turns, and the worm shaft could turn without turning the wheels. Probably not worth keeping any of this as a replacement part source.

So I'd identified the problem. The loco was out of warranty, and the problem was my fault anyhow. Walthers doesn't list replacement parts for locos on its website. I thoujght I might have to find a basket case Mainline SD50 or 60 on eBay and salvage a new truck or something, but that was likely to be expensive. Eventually I contacted Walthers Parts with my problem, and they told me that although they don't list parts on the web site, a single replacement truck was available for a price of around $30 shipping included.

I've swapped out many trucks on Athearn bluebox and even older Atlas locos, but times have changed, and this turned out to be a fairly involved process. One issue was that the truck they sent was wired as a rear truck, not the front truck I needed. (I didn't know the trucks came pre-wired, and the Walthers guy said nothing about it.) So I had to cut the red and black wires from the truck and splice them to the opposite red and black wires from the chassis, insulating the joints with heat shrink tubing.

The tubing in turn prevented the body from sitting properly on the chassis, so I had to fiddle around with making sure the joints with the tubing were out of the way so the body would fit. I finally got things back together and got the chassis running.

I sprayed the front truck frames with a rattle can of Tru Color Weathered Black. The loco is back 100%.

In comparison, here's a 20 year old Athearn RTR D&RGW SD50, a generally simpler model.

I hope I don't need to do too many more repair jobs like this. Unfortunately, this is a rare enough gotcha that it's hard to make a "lessons learned" recommendation, except to say pay a little closer attention when you're at a switch set against your loco, and be careful about leaving power on without activity on your layout.