I have an Athearn diesel that is about 8 years old and it was in storage for 6 of those years. I got it out in October, cleaned and lubricated it, put it on the track and it now makes this horrible grinding noise when it moves forward but not in reverse. I put a decoder in it and after adjusting a few CV’s it was better, but not much. It just sounds like grinding gears in an old '50 Chevy…Any ideas?
Check for cracked worm gear(s). Athearns are notorious for this.
I been using Athearn for the past 50 years and never seen a crack gear…Besides a crack gear goes"thump"thump"thump" and isn’t a grinding noise…
Sounds more like like the flywheel is rubbing the metal contact strip.
Is this a growl or grind? Did you run the engine a bit. Many times they need a “rebreak-in” after years on the shelf. I used to notice this on many of mine. These were Athearns that I fine tuned and did have them run quite well. If the drive shafts/ worm check out OK, do check the motor. Make sure it is seated properly. Those motor mounts can dry out or have the rubber lugs break. I still feel the Athearn growl is more due to motor brush noise than anything else.
Try running up the motor in both directions for a few minutes on a test track. If considerable arcing/ sparking is noticed @ the brushes try dressing up the commutator w/ a pencil eraser. I used to turn/ smooth the staves w/ a strip of worn #600 wet/ dry wrapped over a piece of styrene. This along with other Athearn tuning tips did quiet them considerably. Don’t try the brush spring clipping “thing” unless you have some experience w/ this. A weak brush spring can cause added brush arcing and brush vibration.
The Athearn worm gears are as solid a plastic gear as you’re going to find. I don’t think it’s going to split, short of being chiseled. The axle gears can split now and then, but early P2K is the brand notorious for that.
One of the flywheels could be rubbing the frame if the motor mounts aren’t properly seated, either due to hardening or just being knocked loose. The tuneup tips above are good ones, and there’s a very handy tutorial posted here: http://www.mcor-nmra.org/Publications/Articles/Athearn_TuneUp.html
When you reassembled your trucks, did you put in the thrust washers? Sounds to me like one of two things. The motor tends to push against the thrust washers between the worm and the bearing inside the truck mount.
Depending on how far you disassembled your model, have you checked that there is clearance between the flywheel and the motor frame in both directions? The motor shaft moves a little along its axis and your flywheel could be hitting the frame.
Did you lightly lube the motor bearing from the flywheel side? WIth the amount of storage, the sintered bronze could have developed a bit of a flat which you may have exacerbated a little with your running after those years!
Hope this helps!
Regards from Australia
Trevor www.xdford.digitalzones.com for your interest.
I don’t know the proper name for the part. It’s the pronged cup on the motor shaft that the drive shaft fits into. I broke a finger on the cup and it made a grinding noise in only one direction.
I have a new Athearn GP38-2 that’s grinding in only one direction at low speed. I ran it for a couple hours in each direction on a static stand, lubed it, etc. The worms are intact, I see nothing rubbing anywhere, all the drivetrain pieces are intact and in place, and I glued some foam inside the shell to absorb noise. I did not tear down the truck gears.
Short of remotoring it, any suggestions?
Should I save my pennies for a Kato?
I had one Athearn where the windigs were out of true in the motor. It made a horrible noise. A motor replacement later and it was just fine.
Athearns have historically been noted as “coffee grinders”. Especially the “blue box” kit engines which can run quite smooth or be loud and grindy. Usually the motor is to blame for this but loose or out of alignment splines due to the motor crooked in the mount can cause this too. I’ve got an older GP40-2 that was horrible then I tried running it and its in pieces in a box and with all the new RTR stuff and now Atlas GP40-2’s, it may never run again or may become a dummy.
You mean Proto 2000 is notorious for this. I can’t remember ever hearing of an Athearn with a cracked gear in all my 50 years and reading forums regularly for the last 15 years, not that it couldn’t happen.
I just had that what sounded like a grinding or growling problem with my Athearn, SD45-T2. Looking inside I found the noise was coming from the motor and flywheel assembly. So, I emailed Athearn about it and they told me to loosen the motor screws if their too tight or snug them up if too loose. Guess at the factory in China they screw down the motor screws at the bottom of the frame too much, maybe binding the motor frame, I loosened the screws to where they are just a bit snug. Guess what? The diesel runs smooth now, and no noise. I want to say how great the folks at Athearn for their help.
This is an update on my original post - the Athearn was still grinding so I started tinkering and found that if I raised the motor mounts, the grinding went away - but only if the shell was off. I say that because when I put the shell back on it seemed to cause a binding somewhere in the mechanism. So, I kept tinkering and thought I had it figured out - until a wire broke off going from one of the pick-up clips to the decoder. So, I soldered the wire back on the clip and now the only thing that seems to be getting power is the headlight and not the motor. Frustrated? Yep…But at least the grinding has gone away.
HUH? I dont think so Tim.
I guess is that the motor is not seated properly and the flywheel is rubbing on the shell. Does the unit make the noise with the shell off?
While you are working on your Athearn and you have it apart, consider some upgrades.
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Remove the top clip and cut the spring in half. Repeat with the bottom clip. Be careful though, because the springs have the ability to vanish quite quickly.
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Solder wires directly to the truck halves, rather than rely on the stock electrical design, it is just flawed and the weak link in the Athearn design.
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Clean the commutator with some mineral oil…use sparingly. Remove as much of the oil as you can. The remainder will act as a conductive film that will aid in the performace of the loco.
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Change out the steal wheel half axles with something of quality. NWSL and Proto are 2 good choices.
The result of the above is the following…
A) About 1/5 of the current draw.
B) Smoother ride because of the new wheels as the factory wheels tend to get pitted.
C) More reliable run because of the direct wiring.
David B
Is the plastic universal from the motor to the truck rubbing against the truck contact bar that comes up and around for the top motor brush contact bar? I worked on an Athearn SD40-2 a while back, and it had the problem I just described and made a LOT of noise. It also had problems turning because of that.
By the way, what kind of Athearn do you have? Blue Box kit? Genesis?
David,
What “Proto” wheels are you referring to? I know NWSL makes replacement wheels, but the only other ones I knew of are by JayBee, which are hard to find and not as good quality, IMH experience. Are you referring to Proto 2000, or something else? Would you happen to have a part #? Thanks.
It’s a Blue Box kit that now has a Digitrax decoder in it - which doesn’t seem to be getting power to the motor although the headlight works. I am going to check my soldering job on the wire that came off the other day. I suspected the truck contact bar as well since with the shell off the sound goes away, but when I put the shell back on there is definitely something rubbing - but without a workable motor at this point nothing can be tested. I always like a good challenge…
It is a Walthers part…essentially the replacement wheel sets for their Proto series. I just happen to have alot of them.
The NWSL ones are great and worth every penny.
David B
Ah, I see. That makes sense since the Athearn axle gear is a direct replacement for the P2K. I need to get some more wheels eventually, just wondering what other options are out there. I’ll probably end up ordering directly from NWSL.
Okay - I promise this will be my last update on the Athearn grinder. I decided that the decoder was fried so I purchased a new one today, installed it and wouldn’t you know, the engine ran fine without the shell. So, I ever so gently set the shell without attaching it on the frame, pulled the decoder through the opening in the top and it still ran great!! So, I attached the shell and it still ran great - and I thought, gee, this is mysteriously ‘fixed.’ So, I moved the decoder so I could tape it down and a short occurred cutting off power - just like it is supposed to do. I then started from scratch, removed the decoder, reattached all the clips, turned on the power, it shorted out again through the front clip (black wire) but this time, my new $26 decoder was fried. So, I am permanently shelving the Athearn grinder and moving on…every other engine I own works great and this one will become parts…Ah well, lesson learned.
Did you isolate the motor from the frame? The bottom clip on those blue box units touches the frame for the motor to pick up power in DC. You need to replace the clip with a new one that doesn’t touch the frame.