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Athearn GP40-2 Problems

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  • Member since
    March 2019
  • From: South Lake Tahoe California
  • 188 posts
Athearn GP40-2 Problems
Posted by MetrolinkFan on Monday, May 13, 2019 9:25 PM

I have a SP Athearn HO scale GP40-2 for some reason It is.Acting odd.I runs fine with out pulling any cars.Passenger or freight,But when I do pull cars it will just sit there it will hardly move.The motor runs and spins but not moving on the tracks.What will cause this to happen?Confused

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Monday, May 13, 2019 9:36 PM

You need to take the shell off and see what's going on.

After you have the shell off, turn the fly wheels by hand, and see if the wheels turn, and try turning the wheels by hand.

There is a chance that a couple of the axle gears are cracked, and just "spin" with a load on the loco.

MetrolinkFan
The motor runs and spins but not moving on the tracks.

Once you have the shell off, set it on the track and start the loco, and hold on to it,  to give it resistance, like a string of cars,  you'll get a better idea of what's not working.

Watch the drive shafts, and the worm gears real close.

But again, check those axle gears.  

You should be able to figure it out.

Mike.

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Monday, May 13, 2019 9:58 PM

Probably Mike is right but sometimes DCC is just weird.  Is this DCC?

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    October 2006
  • 89 posts
Posted by trevorsmith3489 on Tuesday, May 14, 2019 5:55 AM

MetrolinkFan

I have a SP Athearn HO scale GP40-2 for some reason It is.Acting odd.I runs fine with out pulling any cars.Passenger or freight,But when I do pull cars it will just sit there it will hardly move.The motor runs and spins but not moving on the tracks.What will cause this to happen?Confused

Firstly, try just one vehicle behind the loco and see if the loco moves and will pull this one vehicle. 

If it does, try adding more vehicles one by one. This will indicate if the loco does not have enough grip to pull a full train. More weight, traction tyres or Bullfrog snot would be a solution.

If the loco moves fine on its own and will not pull even one vehicle, it may be a coupler issue that is maybe lifting the wheels off the track. If this happens check that the wheels are still spinning with the power applied. If this is the case, then adjust the coupler.

Is your track level? If you have a gradient it could be your loco does not have enough adhesion to move itself and a train up the gradient.

Trevor

  • Member since
    February 2008
  • 2,360 posts
Posted by kasskaboose on Tuesday, May 14, 2019 8:47 AM

Here's anothe rvote for removing the shell. You mgiht find that some of the wires might have disconnected from the frame.  I had that on an SD-40 and soldered them back to the area to ensure the trucks work.

Another option is cleaning the wheels by running them on a paper towel with rubbing alcohol.

  • Member since
    September 2002
  • From: North Carolina
  • 1,905 posts
Posted by csxns on Tuesday, May 14, 2019 3:40 PM

BigDaddy
DCC is just weird.

No wonder i never went DCC Cool.

Russell

  • Member since
    July 2006
  • From: Sebring FL
  • 842 posts
Posted by floridaflyer on Tuesday, May 14, 2019 3:43 PM

Sounds like a gear or linkage problem. Doubt DCC has anything to do with it. follow Mike's instructions.

  • Member since
    November 2013
  • 2,775 posts
Posted by snjroy on Tuesday, May 14, 2019 3:57 PM

I would also check the wheels to make sure they all sit directly on track. If not, open the shell as mentioned to see if something is preventing that.

  • Member since
    April 2011
  • 649 posts
Posted by LensCapOn on Tuesday, May 14, 2019 4:23 PM

MetrolinkFan

The motor runs and spins but not moving on the tracks.What will cause this to happen?Confused

 

 

Clear description of a mechanical failure in the drive train. A universal joint slipping on the motor's drive shaft would cause that. It's been a while since I've looked at a Blue-Box, going to N and all, but it may be a flywheel slipping on the shaft. That you can fix with some loc-tight on the shaft. Pop that shell off and see what's slipping!

  • Member since
    October 2001
  • From: OH
  • 17,574 posts
Posted by BRAKIE on Wednesday, May 15, 2019 8:05 AM

If this is a Genesis GP40-2 then send it to Athearn. If this is a older BB check the drive links to ensure all of them are connected--don't chuckle.

I had a BB GP7 that one spline  was no longer connected ..I found the spline  had split and came loose from the worm coupling on the truck.

Larry

Conductor.

Summerset Ry.


"Stay Alert, Don't get hurt  Safety First!"

  • Member since
    March 2019
  • From: South Lake Tahoe California
  • 188 posts
Posted by MetrolinkFan on Wednesday, May 15, 2019 9:38 AM
I fixed it,It was the black cap that goes over the brass.Gear that was on the rear truck.But now I noticed the motor gets hot,and where the Copper part is that has the 2 round little pieces that look like lead pencil ends.It sparks bright light.Why is the motor getting hot what can I do to fix that?
  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Wednesday, May 15, 2019 10:10 AM

MetrolinkFan
where the Copper part is that has the 2 round little pieces that look like lead pencil ends.It sparks bright light.Why is the motor getting hot what can I do to fix that?

The copper part is the armature, and the two little "lead pencil" things are the brushes.

Clean that "copper part"/armature with a pencil eraser until it is shiny.  Make sure to blow the eraser dust out of the little slots that are in the armature.

You can clean the armature by rotating the flywheel by hand, with the eraser against the armature, or you can start the loco, on the track, while running, pick up one end, and hold the loco from going any where, and hold the eraser against the armature while it's spinning.

There is another method but it requires removing the motor, and chucking it in a drill.  We won't go there.

The excessive sparking could mean the brushes are worn, and need replacing.  See how it all works after cleaning the armature, most times, that reduces the sparking.

If this is an older blue box loco, and it still has the metal strip across the top, connecting the two trucks to the motor, make sure that is clean, where it connects to the trucks.

Another trouble with the blue box locos is where the frame sits on the truck.  That area needs to be clean, as that connection is the (-) minus (black) side of the electrical supply.

The metal strip accross the top is the (+) (red) plus side.

If this is NOT a blue box loco, and it is a RTR (ready to run), there is something causing resistance that makes the motor work too hard, and causing the heating.

That could be in the gearing, starting with the worm gear cover that you fixed.  It could also be in the wiring, or the dirty armature.

Clean the armature good, as I mentioned above, and see if that resolves the heating.  SOME heating is normal.  If that doesn't resolve it, than it's time to move on to the next thing.

Also advise us if this is a blue box loco, or a RTR loco, and is it DCC? and if it's a RTR loco, is it "DCC Ready", meaning it has the socket to add a decoder.

I'm trying to identify just what loco you have.

Mike.

  • Member since
    December 2014
  • 443 posts
Posted by Wolf359 on Wednesday, May 15, 2019 1:18 PM

I agree with Mike that your armature is dirty, or your brushes are worn. Or, it could be a combination of both. I would also turn the flywheel by hand and see if anything feels stiff. If it does, put a drop of plastic-safe oil on the motor bearings and see if that helps. If not, then you might have to take apart the gearboxes and clean out any gunk and old grease that's built up, then re-oil and grease them.

  • Member since
    March 2019
  • From: South Lake Tahoe California
  • 188 posts
Posted by MetrolinkFan on Thursday, May 16, 2019 3:17 PM

I have DC only not DCC it's a Athearn SP GP40-2.So far so good no sparking little warm on motor.Thanks for the help cheers

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Thursday, May 16, 2019 3:25 PM

Good deal!  I was trying to figure out if you had a RTR loco, in the yellow and blue box, with the "window" on the cover, or if you had a blue box loco from the 80's and 90's.

Anyway, the armature needs to be checked every once in a while, and cleaned, along with the wheels, and everything else I mentioned. 

As many years as I've run and worked on Athearns, I've never had to replace the brushes.

Good luck!

Mike.

  • Member since
    March 2019
  • From: South Lake Tahoe California
  • 188 posts
Posted by MetrolinkFan on Saturday, July 10, 2021 7:05 AM

I had done a few test on my athearn motors,On a ho power pack.I hoocked up some wires to the motor. Ran the motor for 15 mins got hot what would be causing the to get? Hot like that I have 1 athearn high performance? Motor with dogbone drive shahts.So I put that in my athearn GP40-2 the motor was warm not hot. Looks loike I have to save up some money and buy the. High performance hex drive motors, And dogbone drive shafts

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Saturday, July 10, 2021 8:19 AM

Paging MEL!  Please come to the nearest Kalmbach white courtesy phone and discuss motor conversion! Smile

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