Discussion in 'FAQs' started by Nomad, Dec 4, 2006.

  1. Nomad

    Nomad Active Member

    Anybody use the Ernst re-gearing kit for Athearn diesels? I saw them in the Walthers catalog and the gears in one of my engines is stripped. Also, the ad says for a Athearn 2 truck Mk II. How do I know if I have a MkII? Thanks for any replies.
  2. LongIslandTom

    LongIslandTom Member

    You can buy replacement Athearn gears from places like Discount Trains Online, Horizon Hobbies, etc.

    The replacement Athearn gears aren't very expensive.. A set of idler gears for instance won't cost you more than $3.

    If you are getting stripped gears, it's a sign you are not maintaining your Athearns properly. I got an Athearn GP38-2 I purchased in 1988, and it runs as good today as the day I bought it. Every year the loco gets a complete teardown for a cleaning and lube. It's all in the maintenance!

    Hope this helps.

    EDITED TO ADD: The Ernst regearing kit is for lowering the gear ratio in your Athearn locos to make them run slower. I would not recommend doing it if you plan to run multiple-unit lashups, because you will have to regear ALL the locos.
  3. Nomad

    Nomad Active Member

    LongIslandTom, Thanks for the reply. I think I pushed to hard when I was cleaning the wheels and stripped the gear. Yes, I am looking to get slower operating speeds. It is my Athearn s12 I use for yard switching, so I would not M/U this unit. But I am still not sure if I have a MK II unit.
  4. LongIslandTom

    LongIslandTom Member

    Yes, the Ernst kit will work with the Athearn S12.

    If you disassemble the trucks completely before doing the cleaning, you should not encounter any gear-stripping problems. I'm still a bit puzzled how you managed to strip the gears.. :confused:
  5. Russ Bellinis

    Russ Bellinis Active Member

    I think the mkII refers to the more modern Athearn trucks with the plastic side frames. When Athearn first started building locomotives they came with metal side frams on the trucks and the bearings for the axles were in the side frames. Somewhere in their production lives, Athearn switched over to using bearings mounted inboard on the sides of the gear boxes and plastic sideframes. The exception is the DD40x, which to my knowledge has always had the metal side frames and has never been converted to plastic. I've never used the Ernst supr gear sets, but I think other members of the model railroad club I belong to have used them and told me that there is casting flash on the gears. It isn't a problem if you inspect them carefull and clean the flash off before trying to install the gear sets. I think the Ernst gear sets will work good for an engine that you use for switching. I'm posting a link to the Orange County Module Railroader's home page. If you scroll down the page to "Links To Member's Pages" and follow the link to Jim Fuhrman's home page, he has a lot of information on his pages including a tutorial on how to tune up Athearn engines for excellent running.
  6. 60103

    60103 Pooh Bah

    I redid an SD40-2 with the Ernst gears. The loco runs terrifically slower now, but makes a roar going down the tracks.
  7. Russ Bellinis

    Russ Bellinis Active Member

    Did you clean the flash out of the gears first? The roar may be gear noise from excess flash between the teeth.
  8. doctorwayne

    doctorwayne Active Member

    I installed the Ernst gearing in this older (metal sideframes) switcher that I converted to an NW-2. Other modifications included a very large Sagami can motor and a set of pick-up shoes. It runs at about half the speed of my other small Athearn switchers, also with can motors. The NW-2 doesn't pull as well as the others, though, mainly because the large motor left little room for extra weight, and because of the additional drag from the pick-up shoes. Very smooth running, and no noisier than the other units that have the stock Athearn gearing.


  9. Nomad

    Nomad Active Member

    Thanks all for the advice. Russ, that link is great. Doctor wayne, great pictures as always. 60103, thanks for telling me about the noise, I will look out for that. LongIslandTom, thats the only reason I can think of for that gear stripping,(i'ts the top gear that meshes with the worm gear). I was cleaning the wheels on the track with a paper towel, and one truck would'nt clean up. I saw the wheels were'nt turning and then found the stripped gear.
    Anyhow, I'm going to order those gears now. Thanks again.
  10. Nomad

    Nomad Active Member

    OK, I got the re-gearing kit, installed it per directions, I had the trucks free wheeling enough to push each truck down the track easily. re-assembled the loco and ran it on a test track. ran back & forth great. Very low speed and lots of pulling power. It made a funny noise and quit moving.I looked and the top gear on the rear truck is stripped again. Now this is the new gear that came in the kit. It is the top gear that meshes with the worm gear. I think it's time to scrap this loco!.
  11. Russ Bellinis

    Russ Bellinis Active Member

    I wouldn't scrap it. You may have a defective truck on the locomotive. That is a rare occurance, but you should contact Athearn. If it a new locomotive you purchased, they will stand behind it. If it is an older model or one you bought used, replacement power trucks are available from Athearn for about $4.00 if my memory is correct. The worm gears are also available, if something is wrong with the gear. In fact you can virtually assemble an undecorated Athearn locomotive from parts available from them.
  12. LongIslandTom

    LongIslandTom Member

    That worm is eating up your gears for some reason... I would inspect its threads to make sure it's smooth and are not chipped or dinged. Also you want to look at the bushings holding the worm onto the truck tower to make sure that the worm has just slighly some play in it, but at the same time it shouldn't have too much forward/backward slop.

    You also need to check the hubs of the gears you installed and make sure they are not catching on flashing or something, because if the gears get caught in flashing and stops spinning, it will cause the worm to chew it up.

    And of course, you need to lube the driveline properly.. White grease on the gears and their hubs, and light machine oil in the motor commutators and sleeves.
  13. Nomad

    Nomad Active Member

    Thanks for the advice, but i'm so :curse: with this loco, it's been nothing but trouble since I bought it a year ago. I tried putting a decoder in it, even that wouldn't work. Put the decoder in another engine, works fine. I think I got a lemon. Do they have a lemon law for models?Ha-Ha.:)
  14. LongIslandTom

    LongIslandTom Member

    It is unusual to have so much trouble with a plastic-sideframe Athearn BB unit.. Among all HO scale locmotives out there, those IMHO are the easiest to maintain and keep running in tip-top shape!

    Here's a decent Athearn tune-up guide that might help:

    Does the Gauge have an Athearn tuneup guide in here somewhere? If not, maybe I'll whip out my camera and do a photo tutorial.
  15. Nomad

    Nomad Active Member

    LongIslandTom, thanks for the link. A lot of good information there. OK, I calmed down and decided to fix the engine. But now I have to order another regearing kit. I really liked the way it ran with that kit installed. And new trucks and worm gears. I'm not going to take any chances, i'll replace it all. Thanks again.
  16. Nomad

    Nomad Active Member

    My S-12 lives !

    I got the new regearing kit, and took my time installing it. And I do mean took my time. I would put in one gear only, attach the other side frame, test the gear for binding, if it was ok, then I would add another gear. Took forever to do one truck, but when I was done, the truck would roll down a slight grade by itself. I found two spots on the side frames causing the gears to bind. I now have the best running switcher I have ever had. Slow speed is awesome, in fact that is the only speed it has now, very smooth running, great pulling power, and a lot less noise. I was so happy:D , I also put in a decoder and led lighting.
    I would recomend the Ernst regearing kits to anybody that wants realistic slow operating speeds. Just remember to take your time, and test everything.

    P.S. I would have done a tutorial, but I didn't a camera then.:oops:


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