Athearn Genesis F7A problem

[Butlerhawk]

My F7A does not run properly - when power is on it barely moves, if at all. It sound as though the motor is running; the more power the faster is seems to be running, but the engine will not move. The light does come on. Help - does it need to be lubed, if so, how? (I have never lubed any loco). Any ideas will be appreciated. Thanks for your help.

[Been Nothing Since Frisco (BNSF)]

is the wires going to your powerpack hooked up to the dc side and not the ac side?

[BRAKIE]

I agree it sounds like the drive shafts are disconnected.A easy fix.

[Been Nothing Since Frisco (BNSF)]

is the wires going to your powerpack hooked up to the dc side and not the ac side?

That wont cause the symptoms he is describing....it would just make his loco run at full speed.

David B

Ok, I was just giving him something that may need to be fixed. I the instructions on my starter sets it says to make sure that the wires are connected to the DC side, beacuse if there on the AC side the engin will make nois, the light will come on but it wont move.

[Butlerhawk]

The joint is completely disconnected and was laying loose in the housing when I took the housing off - how can it be reconnected? Does the rear truck have to be removed - if so, how? Thanks for your help.

[jeffrey-wimberly]

I've seen the same thing in instructions from some older Athearn sets and some other manufacturers. Others simply say 'DO NOT CONNECT THE TRACK TO THE AC TERMINALS'. The light will come on but the locomotive won't move. The motor armature may jiggle a little while the windings overheat but that's about it.

[Don Gibson]

I agree with Dave.  If one of the U joints is not connected it will not overcome the drag from the second truck.

Remove the shell to check, and pop back in-place. (No, you don't have to remove the rear truck).

[maxman]

The joint is completely disconnected and was laying loose in the housing when I took the housing off - how can it be reconnected? Does the rear truck have to be removed - if so, how? Thanks for your help.

I don't think anyone has quite answer this question yet.  I don't have one of these engines, but I am assuming (always a bad thing) that it has a hex drive similar to the one shown at the following link: http://www.hoseeker.org/assemblyexplosionAthearn/athearngenesisSD70m75mpg05.jpg

If it is, you'll see that one end of the drive shaft has a hex shape that will engage a socket in the motor flywheel.  The other end has a ball with two pins that will engage a socket at the end of the worm gear shaft.

The easiest way that I see to re-engage these parts would be to pop off the cover on the truck wheel tower that keeps the worm/shaft/bearing assembly in place.  Remove the worm assembly, re-engage the drive shaft into the socket, and replace the worm assembly, and then snap the tower cover back on.  Rotate the flywheel by hand and make sure everything is turning freely.

I don't really see how the drive shaft became disengaged in the first place unless someone had the model open and had the tower cover loose for some reason.  The other possibility if the shaft was laying down in the engine is that the ball end broke off for some reason.  If you take a look at the link you should be able to at least see what the parts are supposed to look like.

Good luck!

regards.

[Butlerhawk]

I was able to reengage the drive shaft without having to take anything apart except to remove he shell. I was able to slip the hex end into the drive and then put the ball w/pin end in place. First time I have ever worked on an engine so was very pleased with the answers to my problem. The loco runs just fine now. I am puzzled as to how the drive shaft became disengaged. Thanks for the prompt answers to my question.

[maxman]

Just out of curiosity, did you have to flex the shaft to get it engaged, or did you slip the hex end into the flyweight far enough to allow the ball end to clear the wheel tower and then slide the shaft into engagement?

I'm just asking because normally there is not enough axial clearance to allow the slide back and forth method of engagement.  If the shaft comes out again, you might want to check whether or not the position of the flyweight is axially correct. 

Regards

[Butlerhawk]

I did not have to flex the shaft - the ball end just cleared just enough to slip into the wheel tower. I still wonder why it disengaged in the first place.

[baldy]

I have a similar problem with a Athearn RTR GP38-2 I am installing a decoder in, however, I have a slightly different issue.  When I removed the motor, the blue stuff that hold the drive shaft in the motor came undone.  By the sounds of it, I should have removed something on the trucks.  I just figured it was like the blue box one, where there was enough slop where giggling would get it out. Anyway, when I reassembled the engine, the drive shift slides out of one of the trucks because the drive shaft slides into the motor.  Simply put, I need to figure out how to reattach the drive shaft to the motor in a way that it can still be disassembled in the future without having other issues (e.g. not superglue the 2 together).  Hopefully this makes sense.  Maybe that wouldn't be a big deal if there an appropriate way to do remove the engine (e.g. bend the shaft a lot) that could prevent this that I didn't do.  I should note that this only happened on one side.

I thought about putting some styrene or other material in the motor hex to prevent it from sliding in.  Any other suggestions?   

Thanks in advance for all your assistance.  As always I find this community to be the best resource out there.

 baldy

[baldy]

I went to my LHS and they suggested Loctite Red.  Anyone try this?