Proto2000 run issue GP9 - run, run, pulse, run, run, pulse

Model Railroader General Discussion (Model Railroader)
1

Hello,

I’ve got a problem. My LifeLike Proto 2000 GP9 (with DCC/sound from the factory) has run like a champ the last couple years since I picked it up- and after a bit of a break lately I pulled it out of the box and had trouble with motion.

It will start moving and after a few seconds, just pulse, and keep moving - pulse (or pause, or jerk) and run again, pause, run, run, run, pause, etc…

Clues for wiser minds than I:

  1. It does it at any speed, from slow mo to full throttle.

  2. The sound continues on - it doesn’t restart as it would if it was losing electrical contact.

  3. It happens moving in both directions.

I did the expected wheel cleaning and track cleaning, and both shine brightly, but still it happens.

Any thoughts ? Has this happened to anyone else? I would be inclined to think there is a wire loose, but I cannot get the shell off to save my life either to check.

Thanks,

railman

2

Sounds lile a DCC BOARD malfunction.

With the shell off and motor disconnected from DCC module, what happend when just the motor gets connected to DC?

3

Hold the engine by the coupler and run it at full speed. If one truck “jumps” and the other doesn’t, then you probably have a cracked axle gear, a common problem with P2K’s. I kinda doubt this is it, though, since the problem was corrected before the sound units came out.

4

Pop the covers on bottom of the drive units and check the axle gears for cracks.

5

Sounds like an issue with the decoders motor drive. I have a loco that did exactly the same thing with an old Bachmann decoder in it. Changed the decoder and it runs smooth as silk.

6

SOUNDS LIKE a DCC board malfunction. What happens when you disconnect the board and connect the motor on DC?

CHOICES: 1. Repair yourself, 2. send to Tony’s, or 3. if under warranty use it and return to dealer who sold it to you,

and, I’d probably keep a spare DCC/Sound module around. Cold solder joints can cause many intermittent, factory caused problems.

7

If these are like my older non-sound units, the shell is held on by the coupler pockets. Unscrew and remove those, being careful not to lose any of the parts that will inevitably fall out. Then you should be able to lift the shell off pretty easily, although it may still be a snug fit.

Personally, I think you’ve got a gear problem. These engines were known for that a few years ago, because the axles developed cracks in them. However, these are new engines, built since Walthers acquired Life-Like, so they shouldn’t be doing this. It may be the universal joint between the motor and the gear towers, but with the shell off you should be able to see where it’s binding.

When you put the engine back together again, use Kadee couplers instead of the ones that came with the engine. I used number 5’s in mine, but I’d probably use 58’s now. These are drop-in replacements.

8

Thankyou all for the suggestions and ideas. I will be taking it apart over the weekend, and when it’s resolved I’ll be sure to post the problem/solution for the benefit of the board.

Thanks again,

9

Hi,

These forums are really a help. I have GP7’s which make a noise and run noisily. The replies posted about the cracked axles make sense. Thanks.

10

Both my P2K GP7 and 9 had cracked gears, and they make a “thump, thump, thump” sound while running. I went to the LTS and picked up some Athearn axels, dropped them in real quick, and they run like champs now. The way I identified the wheelsets with cracked gears was to pull them out and grabbed each wheel to see if they spun in the axel. I guess symptoms may vary, but that is what mine did.