Athearn GP35 "buzzing"

[nwdrummer379]

I bought an HO Athearn RTR GP35 over the summer and when I first started running it it ran just fine. When I threw it into reverse it made this terrible buzzing noise. A month or two went by and the buzzing came back only this time when I ran it forward. Now everytime it runs it makes the buzzing sound. Any idea what it is?

 

[cncproadwarrior]

Sounds like a gear problem. Check the gears for broken/damaged teeth.

 

[UP2CSX]

Are you running DC or DCC? A DC engine on a DCC layout will normally male a buzzing noise, which seems to vary from time to time. If you're running straight DC, it's time to take off the shell and check the drive line and gears. Something has come loose or is broken.

 

[nephthyr]

Agree with above posts, time to take off the shell. My RTR GP35 also made a strange noise so I popped off the shell, think there might have been a wire rubbing against a flywheel or something as the noise went away when i replaced the shell.

 

[Rico]

I just pulled the motor from a RTR GP38 because it was buzzing.
I went thru everything from the gears to the wiring to the brushes.
Turned out to be the armature was loose and rubbing against the magnets.
If you take the trucks off and apply power to the motor with the driveshafts removed and it still buzzes we can cry together.

 

[nwdrummer379]

I'm running it straight DC. Looks like I have a little work to do.

 

[jeffrey-wimberly]

With today's screw mounts one of the past problems of Athearn's GP35 was virtually eliminated. The motor had a bad habit of working itself partially out of the hard rubber mounts used at the time. This would cause one of the flywheels to rub on the frame. While it';s not likely that could be a problem now have a look at the frame beneath the flywheels anyway. I got surprised by a RTR SD40.