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Best Replacement Motors, Drive Lines for Old Athearn Diesels

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  • Member since
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  • From: Portland, Oregon
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Best Replacement Motors, Drive Lines for Old Athearn Diesels
Posted by Attuvian on Tuesday, February 22, 2011 1:33 PM

Time to dump the stock motors and drive lines in my two old Athearn diesels.  One is a GP9 (an Athearn 3150 series unit), the other and SD9 (from the same period).  How about some suggestions for replacements.  With the profusion of stuff out there I'm having a hard time sorting out what to order so please include suppliers and part numbers.  As there are multiple options, perhaps some of you will also share some pros and cons when you see what others are recommending.  You may also want to share preferences for specific brands & IDs of silicones or other goos being used in lieu of the original Athearn motor mounts.  Don't want to dump the time and affection invested in detailing these two units and have found that the major source of noise in them occurs before power is being applied to the trucks.  The Pearl Drops controversy aside, I've got more issues that the old Athearn Maintenance/Upgrade program will remedy.  Thanks, all.

John in Oregon

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  • From: Shawnigan Lake, BC
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Posted by rogertra on Tuesday, February 22, 2011 1:41 PM

Are they in fact worth rebuilding, given that by today's standards, they're rather poorly detailed?

After all, tboth the original Athearn GP9 and the SD9  bodies are to wide so as to accommodate the old motor.  Eight feet wide instead of seven feet wide?  Might as well just purchase replacement locomotives, and get much better detail, probably DCC ready or even installed and none of the work involved in re-motoring.

Cheers

Roger T.

Home of the late Great Eastern Railway see: - http://www.greateasternrailway.com

For more photos of the late GER see: - http://s94.photobucket.com/albums/l99/rogertra/Great_Eastern/

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Posted by MisterBeasley on Tuesday, February 22, 2011 1:44 PM

I have a pair of old Athearn GP9s from the 1960s.  I looked into remotoring and replacing the wheelsets.  Then I looked at M.B. Klein (www.modeltrainstuff.com) and found brand new Proto GP9s for less than the cost of upgrading.  They were "blowout" sale items, out-of-production models, but both M.B. Klein and Trainworld (www.trainworldonline.com) do this a lot.  One of the old Geeps was converted to a dummy, but both that one and its unconverted brother sit in a box beneath my layout.  I bring them out when I'm gluing down track and need some dead weight while the glue sets.

I upgraded an Athearn F7 from the same timeframe by replacing the entire chassis.  Unfortunately, Athearn doesn't sell the chassis anymore, but that might be another option if you can find one that fits.

It takes an iron man to play with a toy iron horse. 

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Posted by swampsavage on Tuesday, February 22, 2011 2:04 PM

Thanks guys,

I was also considering repowering mine but, sometimes can't see the forest for the trees.  I think I'll just give them the usual overhaul (oil, grease, hard wire to trucks etc.) and relegate them to sometime operation.  I agree about the newer stuff being more detailed and better running.  

John - W Jackson County GA

Modeling Milwaukee Road up to the 60's

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Posted by Attuvian on Tuesday, February 22, 2011 2:49 PM

Thanks for your observation, Roger.  Indeed, there is the issue of the non-proto hood width and the the DCC, readymade detail and out-of-the-box-and-you're- done with the new stuff, if it's available in your chosen road paint schemel.  On the other hand, there are also opportunities to do something with the hands and the mind that are lost in the process.  And some of those benefits are transferrable to other layout building tasks.  I have considered the extra expense in both time and dollars (and may indeed revisit them again!), but being and old-school kind of guy I'm suspicious that there are any number of other "costs" in adopting the easy way out.  Guess it's just one of those philosopical approach issues among model railroaders.

John

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Posted by BRAKIE on Tuesday, February 22, 2011 3:45 PM

John,Actually most guys just replace  the stock motor with a Kato motor and use the newer drive lines.

If you enjoy that facet of the hobby then by all means go for it..

I will be replacing these crappy grab irons on my P2K GP7 with Detail Associates grabs so,nothing is perfect..

 

Larry

Conductor.

Summerset Ry.


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

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Posted by Forty Niner on Tuesday, February 22, 2011 3:54 PM

How about using a KATO motor and a Trains Unlimited shell if you want to use the Athearn drive. I did that years ago to several of mine but of course the expense was less than it is today. The KATO motors were $15.00 and the Trains Unlimited shells were also $15.00 so I had scale width hoods with the extra details and excellent performers for a $30-35 investment.

Would probably cost you more in the area of $50 today...........

Mark

NMRC

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Posted by Darth Santa Fe on Tuesday, February 22, 2011 4:59 PM

Let's see how much money I can help to save you on this...

MOTOR: $5.70 + $1.73 shipping (bearbon, good guy to deal with)
FLYWHEELS: $7.95 (come in pairs, have Athearn style couplings pre-installed)
MOUNTING MATERIAL: $12.33 (comes in 10oz. caulk tube)

You can use the original Athearn universals. To make them quieter, put a little piece (1/2") of tissue on the end of the spline, and stuff it into the cup. It might take a couple tries to get it adjusted right.

So for your two units, the two motors, flywheels, and mounting RTV come to a total of $39.63 before shipping. That's less than the cost of a single repower kit from A Line, and the RTV will dampen motor noise and vibration.

_________________________________________________________________

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Posted by Attuvian on Tuesday, February 22, 2011 6:03 PM

Thanks.  I'll check these out when I get home from work - and am allowed access to these URLs. Are you saying that the rattle on the Athearn drive line is largely at the point where they connect to the flywheels?  Interesting idea on the tissue (facial?).  I would think it would get beaten to death sooner or later and not only lose its effectiveness but trash the unit's innards with fibers.

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Posted by Attuvian on Tuesday, February 22, 2011 6:06 PM

Got a part # for that Kato motor?

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Posted by Attuvian on Tuesday, February 22, 2011 6:07 PM

Got numbers for the newer drive lines?  Thanks.

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Posted by Darth Santa Fe on Tuesday, February 22, 2011 7:39 PM

It's actually not the ball couplings. It's the long straight bar in the middle. It's usually pretty loose inside the end coupling, so sliding it back in the socket with a piece of something like Kleenex can help to tighten it up without restricting forward and back movement much. It looks like the ones in the GP9 and SD9 are the shorter two part ones, so they're an easier fix than the three part universals in longer diesels. If you want to know what I'm talking about, here's a diagram of the GP9 (parts are shown as the "coupling" and "spline").

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Posted by Forty Niner on Wednesday, February 23, 2011 5:59 PM

You need to go to the KATO website to get the part numbers you want, but................if Darth has an alternative on the motor I would look into it as he has already done this and I'm sure he wouldn't send you after a junk motor just to save a few bucks.

I would suggest you check out his suggestions and with the money you can save you could get yourself those Trains Unlimited shells and have the scale hoods and the extra details which would "approach" the area of the Proto engines. They're nice looking shells and are designed to work on the Athearn chassis.

Any further questions ask Darth as he has "been there, done that" already.

Mark

NMRC

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Posted by Attuvian on Wednesday, February 23, 2011 8:03 PM

Darth -

Forty Niner has encouraged my snatching up the Igarashi motors you suggested.  At this price I might be inclined to pick up more than two and tinker with dropping one into an old Roundhouse Prairie.  My only concern with the Igarishis is that the shafts are only a quarter inch long.  As the A-line flywheels are 11/16" long that leaves about 64% of their length hanging out beyond the end of the shafts.  I would think that lends itself to a potential wobble issue.   And how is the bore on the far end of each flywheel prepared to take on the business end of the spline coupling (let's presume I'll use the Athearn drive line parts as you suggested)?

John

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Posted by Darth Santa Fe on Wednesday, February 23, 2011 10:07 PM

As long as the flywheel is pressed on straight (a vise works well. Just remove the plastic couplings first if they stick out), wobble won't be a problem. I used an Igarashi motor not long ago in an Athearn F7A, and the flywheels didn't have any issues with being off-center. Igarashi motors are used by BLI and a few others, and I have yet to hear of a failure.

A Line makes universal couplings identicle to Athearn's, and the flywheels come with the motor-end ball coupling pre-installed. The Athearn couplings will snap right on, and if your diesels came with stock flywheels, you shouldn't even have to cut the universals to length.

One thing I should note about custom made flywheels, like A Line's and NWSL's, is that sometimes the balance can be off a little (causing vibration and a rumbling noise). Drilling a hole a little at a time in the heavy side of an off-balance flywheel can fix it, but that's only if the flywheels have that problem.

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