I have an Athearn RTR SD40 (Soo Line) that runs VERY SMOOTH but makes a very obnoxious sound while running. At slow speeds: BUUZZZ BUUZZZ BUUZZZ BUUZZZ… At medium speeds: BUZ BUZ BUZ BUZ… At high speeds it makes a quieter grinding sound. The buzzing is medium-high pitched and speeds up as the speed increases. I’m very disappointed at Athearn. [|(] I can’t post a video because my layout is in-operable at this time. Here are some pics of the motor:
Does it make the same buzz while running it with the shell off the chassis?
Any point where a wire can come into contact with rotating parts in the drivetrain could be the sources of the noise. The fact that it varies with speed is a good indicator that’s what’s happening.
Does it still make the noise with the shell off? If not, then it’s a case where the pressure from the shell pushes whatever is making noise into the rotating path. Adjust the most likely culprits and try again. If it makes noise with the shell off, then it’s usually easy to spot.
The engine still makes the exact same noise with the shell off.
Hi,
Have you tried running it from a 9v battery against the wheels, or better yet a 9V cap with test leads to an input. (with the Shell off)…
Then, hold it by the tank to hear & possibly see the noise -or-
Hold it by the motor, to see if it motor to frame vibration sound
Even the lowly 9V battery can be a good tool for testing.
If not, try wedging a toothpic around the motor & then running it on the test track, then flaring out anything that can touch a rotating part, away from it, (vibrations brings things together)…
If still no resolution; then try taking one half shaft out at a time, until you are left with just the motor spinning…
It’s all a process of elimination…
I faceciously told a buddy I had loud ditchlights once…
He took it as the truck gear nosie, not the brightness, that i really meant…
Best of luck,
Is it noisy in both directions? I had a gp40x that was noisy in only one direction and I found that one worm gear was missing a thrust washer as soon as I put one back in, it solved the problem for me.
I recently purchased an Athearn Genesis SD7Mac. The motor had a squeaking sound that was clearly linked to the speed. I took out the motor, and verified that it was squeaking by itself (I suspected something rubbing very slightly with each revolution) I called athearn, and they told me to send in the motor ( I was happy to do this, as I’m disgusted by the throw away society we’ve become - I was happy to fix it rather than return the locomotive.) A few days later, I received a small package with a new motor. Good on you, Athearn! Point being, they want to help you fix it, and make things right. Try calling their customer service number and see if they can help troubleshoot…
By any chance,do you see,excessive sparking at the motor commentator where the brushes are,if you do,clean it with Alcohol,and another,your motor shaft bushings ( bearings) could use some oil on them,they could be dry and that will cause the motor to work harder and make a buzzing,whine noise…Give those two things a shot and see what happens…
Cheers,
Frank
Ok, there is no sparking, but weirdly enough, the engine runs QUIET in reverse, no sound at all, also when i push together the two plate on the sides of the motor, the sound dies down! I have lubricated this engine and done proper maintenance.
The OP should get to another layout and post video with sound of the noise.
Sooline720,
OK,So you say,you did indeed,lubricate the motor shaft bushings on both sides of the motor shaft?? And when you squeeze,the sides of the motor the noise gets,quiet,more than likely than the motor bushings are worn,from running a lot dry,they are only bronze and will wear,without proper lube,you could probably use a new motor,much easier,than trying to repair that one. When you lube those bushings,you should turn the motor in a vertical position,even when it is running,or turn by hand to both sides,of the shaft…So the lube flows into the bushing,not just being on the outside of it… Running in either ,forward or reverse,if it runs quiet,in one direction and not the other,is a very good indication,that the thrust bushings are worn…This is just the motor,nothing else attached to it,no drive line,per-say…
Cheers,
Frank
Everything was lubricated properly but the problem is that i don’t know how to take apart a motor and put it back together again. [sigh]
Sooline720,
Sorry to say,I did have a link stored in my favorites,for that,but now I can not even get it myself,it shows that it is no longer available,Rats,for both of us…
Cheers, [D] My suggestion,would be to replace it,it does look pretty worn from the pic’s,they are really not that all expensive,Your call…
Frank
Don’t try to take the motor apart it isn’t worth it. Get a replacement they are cheaper than the headaches you’ll have trying to repair the motor. An Athearn replacement or a Kato motor will get you back in business.
Joe
First thing that came to my mind when I read the opening post … you’re not running it on DCC with address 00 are you ?
Sorry … had to ask …
Mark.
Mark
Interesting observation. I saw the DC circuit plug in the socket and just assumed that he was DC.
Joe
There are a few more culprits for noisy Athearn RTR drives to investigate if you want to.
It could be a burr on one of the worm gears. I have personally seen this a couple times with Athearn RTR’s. The new worms are white slippery plastic instead of brass, and sometimes when they come out of the mold, they have an imperfection or a burr. This imperfection can cause the engine to make noise in one direction only as only one side of the worm is in contact with the spur gear when it’s traveling in one direction or the other. I have been able to fix one burr by filing it off. The other was impossible to fix, and I replaced it with a brass worm from an old Athearn BB I had.
Another possibility might be that the motor is misaligned. Loosen the screws that hold the motor to the frame. Place the loco chassis on the track and run it at full speed against a bumper. As it’s running, gently grasp the black plastic ends of the motor and start gently twisting the motor ends one way then the other. You should hear the motor sounds increase or decrease (and RPM’s slow or speed up). What you’re looking for is a “sweet spot” were the motor sounds decrease and almost becomes silent. At this point, shut it down and take some 5-minute epoxy and glue the black motor ends to the brass-colored center piece (don’t over do it). This will hold the motor in alignment. Then after it sets, gently tighten the 4 screws. I’ve done this a couple times, and I was surprised at the quality of the results. It made a couple Athearn RTR’s sound really good for me.
It could also be the brushes. There’s two modes of thought here: cut the brush springs in half or cut the motor brushes in half (the “Jim Six Fix”). Cutting the springs is tricky because it’s hard to get both equal (and equal pressure is important). That’s why Jim