I currently have a used model Big Boy from 2013 maufactured by MTH Trains, and it's currently having some issues running. It has been suffering weird speed loss, it's not accelerating to its full speed. Even when it's hauling no rolling stocks at all, it's going rather slow. Both on DCC and DC, it's suffering speed loss. Not to mention it's drawing in so much power from the layout. 0.75 amps minimum in comparison to 0.30 amps to all my other locomotive. Heck, the smoke unit isn't even turned on! And the amps doesn't go down with the sound off. I restarted the decoder and all of its functionality so many times, I even lubricated the wheel's driving rods, and gears, but nothing is working!
I already talked to a bunch of people about this and they are saying it may be a combination of the motor not operating well, as well as the Decoder needing to be replaced. If those two are the case, I need to ask, what are some good dcc decoders you reccomend to replace the current proto-sound 3.0 that's currently in the tender? And does anyone have a good guide as to how it should be done? Also, I need help in the matter of opening the main engine's shell to get to the motor. However, the assembly of the engine is so bizzare I can't seem to find the right screws to unscure, and where to start. And I cannot use the model's parts list and explode view diagram because it doesn't help since the parts seemed scattered in the diagram. And I do NOT wish to send it to repairs because it would take so many months to get it back, especially in this current climate we are living in. Can anyone please be able to give me some guide as to how to open the engine and get to the motor for analyzing and potentional replacement?
Hi, the decoder is very likely fine. If an MTH decoder goes bad it will usually just no longer respond. High current draw is unfortunately normal for MTH engines even with the smoke units off.
I agree with the others that there is likely something wrong with the motor or gears. Your best bet will be to disassemble the engine, and try to turn the motor shaft with your fingers. If its very hard to turn, then somethings wrong with the gears (and we can diagnose it further). If its easy to turn, then your motor is faulty and should be replaced. Personally, my bet is on the gears. As far as disassembly, I really cant help you there. Either someone with experience with a MTH big boy, or do some research online. I DO know that MTH stole BLI's old tooling for their big boy, and if they didn't alter anything, there should be a screw underneath the steam dome. Here's BLI's exploded diagram. If MTH modified anything though this diagram wouldnt be useful: http://www.broadway-limited2.com/support/UP%20Big%20Boy%20Exploded%20View%20(Locomotive).pdf
Good luck!
Charles
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Modeling the PRR & NYC in HO
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Dried up lubes, a motor that needs replacing, or something else is rubbing and causing friction...except that often has accompanying heat and noises.
The decoder is digital. It works or it don't. No grey.
Trainman440 Hi, the decoder is very likely fine. If an MTH decoder goes bad it will usually just no longer respond. High current draw is unfortunately normal for MTH engines even with the smoke units off. I agree with the others that there is likely something wrong with the motor or gears. Your best bet will be to disassemble the engine, and try to turn the motor shaft with your fingers. If its very hard to turn, then somethings wrong with the gears (and we can diagnose it further). If its easy to turn, then your motor is faulty and should be replaced. Personally, my bet is on the gears. As far as disassembly, I really cant help you there. Either someone with experience with a MTH big boy, or do some research online. I DO know that MTH stole BLI's old tooling for their big boy, and if they didn't alter anything, there should be a screw underneath the steam dome. Here's BLI's exploded diagram. If MTH modified anything though this diagram wouldnt be useful: http://www.broadway-limited2.com/support/UP%20Big%20Boy%20Exploded%20View%20(Locomotive).pdf Good luck! Charles
I've managed to successfully remove the shell of the Big Boy with ease and without much trouble. I was careful doing in and managed to get to the motor itself. I rotated the shaft with my finger and the it seemed to spun without any difficulty. So I assume the motor must be faulty.
I already checked the gears and they seem to be working fine, even lubracted very recently.
What do you suppose my next step is? And if I need to get a replacement motor? Which one should I get?
I would still verify that it is indeed the motor. Can you hook it up directly to a DC power source and dial up about five volts or so, and see if it spins madly. It should, but if it won't, it is probably due for replacement.
I operated the engine in both DC and DCC. I tried it with just the engine alone, and it seems to be running fine, but not at full speed. I tested it by pushing the engine a little while under power, and saw that the engine has greater speed than what I was seeing on its own. Putting some rolling stocks slows it down significantly, both in DC and DCC. Especially the latter.
Any chance you have a cracked coupling in the drive train that is just allowing a shaft to spin rather than turn at the same speed as the motor?
If you hold the loco still with one hand and take the other to turn the motor slowly does it turn freely? If so, something is slipping.
Don't know about the inards of MTH but had another brand and the metal shaft became disconected from the plastic end, you couldn't tell it either when removed unless it was turning under pressure.
My usual approach to situations like that is to do this:
1) Clean the wheels and the track
2) Reset de decoder
3) Relube the bull gears and the driver bearings
4) Remove the shell, run the engine. Check for anything odd. Lube the motor shafts and universals while you are in there.
5) Turn the motor manually to check resistance (already done!)
6) Remove the motor and push the engine, gently, on a flat surface. This is to test for binds in the running gear.
7) Check the motor on the workbench. It is unlikely that you have a motor problem, but who knows. If the motor does not reach a high speed on the bench, then you need to change the motor.
8) If the problem remains, I would install a low cost decoder and see if the performance improves.
Simon
Awesome! Yea I agree with the others, you got one of two issues.
1. (more likely) you got a cracked gear of sorts. Using moderate pressure with your fingers, try to spin the wheels by pushing on the drive wheels themselves (not the motor axle). These wheels should NOT be able to be spun. IF they do spin, a gear ix cracked, meaning the gears are slipping on the wheels.
2. a bad motor. Do what others have said above, and with the tender detached, apply 5-10V directly onto the motor leads. See if the motor is extra weak (for example grab onto the spinning motor axle and see if the motor stalls with a slight touch). As far as finding replacement motors, send us a photo of the motor and we can find a suitable replacement.