Growlin' GP20

Discussion in 'FAQs' started by Herc Driver, Jul 8, 2007.

  1. Herc Driver

    Herc Driver Active Member

    I just bought a LifeLike Proto-N GP20 and have been running it for the first time today. I growls somewhat loudly when it enters a turn. Along the straight track, no more noise than any other diesel, but in the turns it growls more loudly than it's running mate, another LL GP20. It also slightly slows down when entering the turn too...not a whole lot, the slow down is barely noticable. I added a very small amount of oil to the gearing as it really seemed very dry. (I don't know exactly how long this diesel sat on the store shelf.) I checked the wheels with a gauge, and they're lined up straight and set according to the NMRA standard N gauge. I've never had an engine be this noisy in a turn like this...anyone out there seen this?
  2. Bones

    Bones Member

    I had an SD-40 that did the same thing. It had a click, and a grind...

    The grinding was from rough gears. It just needed to be run-in. I used some gun barrel lapping oil with 30 minutes of running to smooth them out. (I don't reccomend this. Improper use can ruin your loco.)

    The clicking was a small bur on the worm gear. I took a jeweler's file to it and gently smoothed the edge. No more click.

    Does it do this in Left and Right turns? or just one direction?

    Check to make sure your trucks clear the frame.
    Make sure there's no flashing in the gear case. Flashing from the injection molding can cause grinding sounds, and gears can shift side to side a bit when turning.
    Also check the trucks. Make sure the wheels dont have rough spots that contact something else while turning.
  3. Herc Driver

    Herc Driver Active Member

    Very good ideas that I'll check out...thanks. On first inspection, there seemed to be no reason for the grinding...and after a while of running the sound seems to be getting less noticeable, so it may be just taking a while to work out the kinks in the system. I've run it fwd/rev, fast/slow, both directions around the layout too. It traverses all the turnouts with no problem, pulls and travels in both directions on the layout just about the same. I'll take a look inside and see if there's a mechanical problem, but so far after a while of constant running, I'm encouraged that it's growling less than it was before.

    Thanks for the good ideas though - I appeciate it.
  4. Ray Marinaccio

    Ray Marinaccio Active Member

    Good advice Bones.
    I have an Atlas GP30 that had the same symptoms. It turned out to be flash on the drive shaft.

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