Removing a Athearn Motor

Affiliate Disclosure: We may receive a commision from some of the links and ads shown on this website (Learn More Here)

#1
I have an HO scale switcher that is very noisy. Bought it new years back, always has been.

Finally got around to checking it out, don't run yard switchers much, and the flywheel is hitting the shell. The motor is loose which is probably allowing this but how do I remove and especially re-install it?

It appers to have been seated with the plasitc plugs using a press and possibly heat applied to expand the plugs on the bottom.

I have read about how to do it, just pull, working it back and forth, probably I am just not pulling hard enough, but even so how do I re-seat the motor after I pull it out? Won't the plugs become damaged in removing it?

I thought about just holding it down while applying some hot glue to keep it seated and hope this will control the flywheel.

I know this is the problem because with the shell removed it runs quiet and also you can see inside the shell where the flywheel has been hitting.

I have worked on locos before but have never got down to the point of where I have had to pull a motor.
 

Larry

Long Winded Old Fart
#4
The reason the motor is hitting the shell; it might be in backwards or it's a different shell for that frame. Also, there's a ground prong that sticks out under the motor(brass) that contacts the frame for DC operation. Just grab hold of the motor & wiggle it & it should come out real easy. You should be real careful that you don't break off the shafts going from the motor to the trucks. the noise is from the motor sitting in the frame crooked.
 
#5
Their just press-fit plugs, through a couple hundred times you might wear them out but not just a couple times. There is 2 of them one on each side. If you want I can take some quick snaps of the process
 
#6
I have had it stripped down to where there is nothing but the motor and flywheels on the frame.

I wouldn't risk trying to remove it with the trucks attached.

The motor could be in backwards I suppose, it doesn't run "backward" so to speak. It is just loose which allows so much vibration the flywheel hits the shell I think.

If I do take it out I am of course going to hard wire the ground.

Good to know they are just press fit plugs, thanks for all your help on this.
 

CBCNSfan

Registered Member
Staff member
#7
The rubber mounts harden in time and lose their flexibility. That's probably what has happened.
When I rebuild my Athearns I discard the rubber mounts, cement plastic strips in their place, position the motor, drill and rap the motor feet/pads whatever and use screws to secure it to the plastic strips. Attached is a photo of the screws but I'll have to do some searching to find a photo of the strips cemented into place.
This also lowers the motor so the shafts are more horizontally aligned. Makes for better running.
Here's a link to a tuneup page that may be of some help to you.
http://www.mcor-nmra.org/Publications/Articles/Athearn_TuneUp.html#TRUCKS
 
#8
That's probably what has happened, the switcher is about 15 years old. Sounds like a great way to re-mount the motor, though. The way you described.
 

ICG/SOU

HO & O (3-rail) trainman
#9
Get a pack of these or these. The latter are the new type, which screw in. I keep a couple on hand since I have some of the older motor mounting pads, and have broken them before.

If you get the new type, don't screw too lightly, as the motor will vibrate. If you screw it too tightly, then the motor can bind and have issues too.
 
#11
Take a close look at the flywheels. I have several old Athearn diesels and more than one vibrates and wobbles because the FLYWHEELS wobble and vibrate. In some cases, I've fixed the original, in others it worked better to just buy new turned brass flywheels.

With the motor mounted with silicone and balanced flywheels, they run much better.
 
#12
Next time I tear it down I'll check the flywheels and see. I'll hold down the motor and see if the vibration goes away, right now I'm rigging up some plastic sheet material and spacing it to represent the inside of the shell.
 
#13
Just a follow up. Got it fixed. Seated the motor with a small amount of glue and also oiled, then greased the motor bearings. I think the motor bearings are a bit too oversized for the shaft, usually a fine oil will work but I had to go back and use some Atlas grease.

Thanks for your help on this.
 



ModelRailroadForums.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com