Train Losing Connections around Curves or Switch

Yup, this happens with my new Susquehanna S-4 as well. I run Legacy, using Atlas track, and one small area about 6 inches in total, railsounds restart and lights blink. I have all Lionel legacy engines and this is the only one this happens with. I clean the track frequently and that helps and use the electric lube on rollers. But, I am convinced it has to do with these loco's only having 3 pickup rollers! I have the PRR version from 4 years ago, with 4 rollers, and it runs fine.

Thanks - I think it has something to do with the rollers -

I replaced the rollers and its works better - The hobby shop I buy from, smart folks in the industry thinks maybe more weight might do. the trick

I have 7 S2/4’s. I’ve experienced this same problem and pulled off the garbage oversized traction tires Lionel puts on and replaced them with MTH diesel tires. Problem solved!

Thanks I will try that out

It won't help this situation but I would reduce the track voltage to the 18v that Legacy locomotives are designed to run on.

Otherwise ,you may have more serious issues that changing traction tires won't fix

Thanks Rick and Jim Z

I tried the MTH traction diesel it got better but around a certain curve it dies

Rick what is the deal with 18V - is that for all Legacy trains?

Mine act up where I have isolated rails for blocks on curves. When the lead truck enters the block, the common is intermittent and power reliable power lies solely on the one axle of the trailing truck. I have to clean the track in these areas more often, but it rarely stalls. When it stalls, take a jumper and connect one side to a good common and touch the other side  to one of the wheels without disturbing the locomotive and see if power restores. At least you’ll know your looking at the problem correctly.

Legacy engines are designed to optimally run on a constant 18 volts. Any more and you risk damage to electronics.

When my MTH Z-4000 is set to 18 volts, I typically measure 19-20 volts around the track, which means the transformer meters are not as accurate as my DVM, so I adjust the transformer throttles downwards to read 17 volts. This fluctuates a little with different trains and loads, but the point is to rely on the DVM reading (assuming it's a good /high quality one) and not the transformer. 

I had a Legacy 0-8-0 that would stall after it stopped on a straight piece of track in the process of changing direction. Both outside rails connected. Just moving the engine slightly to one side restored power. 8 drive wheels. 2 with rubber tires, 2 blind drivers and 2 flanged drivers that you were relying on to create the majority of contact to the rails. The engines only connection to the tender was for sound purposes. The simple fix was a short piece of wire with a ring at each end to connect the 2. Attached to 2 convenient screws and now the engine had 8 more wheels hitting the outside rails. The recent 0-8-0’s went back to a wired tether just for this reason.

Had a MTH DL109 that would stall at crawling speeds. Ran great at medium and up speeds. Final solution was to let it run at a good clip for an hour. I’m guessing the traction tires must have settled in as it was fine after that.

I believe Jim Z was right on with his diagnosis. Connect the outside rails with a jumper and then see how it runs.

@NYC Z-MAN posted:

I have 7 S2/4’s. I’ve experienced this same problem and pulled off the garbage oversized traction tires Lionel puts on and replaced them with MTH diesel tires. Problem solved!

As I am not familiar with MTH parts, what is the part number for a the MTH traction tire?  as I would like to order them and try..thanks

Jim Z - I did what you said I let the train run when it hit that curve it stalled. I took a banana clip and touch the two outside rail together and power came on and for the first time since getting this engine it went around the layout and into the yard with no issue.

Now what do I do, my signal system is dependent on having one of the outside rails isolated?

It was great to see the train run with no issue - thanks for that - I was so frustrated thinking it was a problem with the train

Dave C can you send me a picture of what you did not sure if that can work for me

Again thanks a lot Jim and Richie C. I made sure that the voltage was never above 18V - thanks for the info

Do you really need to have one entire outside rail isolated on the whole layout?  You will need to sacrifice a few sections on the layout that you normally use for signaling, and wire those few areas for common on both outside rails.  There are ways to get signals to activate and change states, using short isolated sections and relays wired for latching, etc., rather than a long section of track.