OvermodEd will have pictures showing how to remove and dress the brushes, or identify surface problems on the commutator surface that cause high-frequency vibration in one direction.
Unfortunately it is the composition of the brushes, from what I understand they were too 'soft', that causes the commutator to gum up, overheat then wind up looking like this.
Athearn DC-motor Roco by Edmund, on Flickr
Note the melted solder 'slung' onto the inside of the end housing:
ATH_DC-motor4 by Edmund, on Flickr
In some cases I've cleaned the commutator, reinstalled the brushes after rotating each one 180° to even the wear but the swueal returns after a while and eventually the motor increases in current draw until it melts the windings or wipes out the decoder.
ATH_DC-motor1 by Edmund, on Flickr
Regards, Ed
I thought someone had already mentioned the commutator and brushes as a potential source of 'unidirectional' squeal.
When you have the shell off to lubricate the worm and 'thrust surfaces -- run the chassis around and listen to see if you can isolate a source of squeal in the motor. Ed will have pictures showing how to remove and dress the brushes, or identify surface problems on the commutator surface that cause high-frequency vibration in one direction.
OldEngineman Another area that might need oil are the bearings on either side of the worm gears. They can get "dry" and squeal. You'll have to take the shell off, and "get to" the worm gear covers and pop them off to expose the bearings...
Another area that might need oil are the bearings on either side of the worm gears. They can get "dry" and squeal.
You'll have to take the shell off, and "get to" the worm gear covers and pop them off to expose the bearings...
ok thank you.
I really appreciate that photos, that makes it clear how it is latched, thank you. I have removed the shell to check for any binding or wires rubbingetc, while i was there I put a drop of oil on the motor bearings but it made no difference. I will try oil on the gears, thank you again.
I thought I had a photo of a Genesis Blomberg truck on hand* but that one escapes me. Yes, you can carefully release small retainers on the bottom cover of the truck. I'm not sure if lubing here will cure your squeal, I've had problems with a few vintage Genesis motors.
If you remove the shell you can get a TINY drop of oil on the motor bearings and worm bearings. Some of the Buhler and Roco motors that Athearn used had brushes that weren't up to the task and the commutators would fry.
* So I went to the shop and made some...
Here is one latch 'unclipped':
Genesis Blomberg CoverLatch by Edmund, on Flickr
And the cover off:
Genesis Blomberg Cover by Edmund, on Flickr
Latches are shown at all four corners.
Genesis Blomberg Cover Off by Edmund, on Flickr
The inner square pins hold the sideframes on.
Good Luck, Ed
I have an HO Athearn Genesis GP7. In one direction only it has a squeal sound and i thought I should try putting oil on the gears. No other obvious reason for the noise that i can find.
Can the gears be accessed by removing a cover similar to the old blue box locos? It does not seem so. Or do i have to disassemble the loco to get to the gears?
Thanks for any assistance.