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Remotoring An Athearn SD75I

Bob
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A few weeks ago I picked up two Athearn SD75Is in Canadian National colors.  They look great, and being in Minnesota, anything CN or CP can sometimes be hard to find, so I feel like I lucked out a little bit.

All I can say about how they run is that it's OK, but it's nothing to write home about.  Compared to the Katos I have, well frankly there is no comparison.  I was wondering if anybody has ever remotored one with a Kato mechanism or if another company offers different motors for them.  I know things like this are available in HO (from what I've read), but have no idea where to start in N.

 Any thoughts?

Either that, or anybody interested in a couple of sleek-looking CN SD75Is?  Laughing


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Submitted by Bob on Wed, 03/12/2008 - 09:27.

philhendry
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 Joined: 2007-03-15
Grease!

I own three Athearn SD70I/SD75I models.  I wasn't very impressed with them to begin with.  They all ran an awful lot better after I'd stripped them down and cleaned out 95% of the grease.  They were all very badly over-lubricated - it was everywhere, clogging everything up.  After that, they ran, and continue to run, fine.  They run smoother than my Atlases and Lifelikes, but slightly noisier than my Katos.

Phil 


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Wed, 03/12/2008 - 10:33

siderod
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I personally own three of

I personally own three of them, and have worked on a dozen more. They're good locomotives once they get run in and cleaned up. When I opened them up to install a decoder, I ran a pumice hand cleaner through the trucks to deburr everything. I removed all the grease from the bearing blocks and worm gears, washed the pumice from the trucks, and regreased everything with LaBelle's oils. All but one worked beautifully on my first attempt. One was a little more stubborn to cooperate.

 

AR 


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Wed, 03/12/2008 - 11:39

Bob
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 Joined: 2008-01-11
Cleaned 'em up, batting 1 for 2

Cleaning definitely helped out one of my stubborn CN units, but the other one is still running like junk.  You guys can see a report here:

http://www.nscale.net/blog-entry/bob/2008/03/27/four-phoenixes-rising-ashes

 I have not tried the pumice in the trucks yet but did remove a massive amount of junk from the worm gear assemblies as well as the truck gear box.

It seems the motor is getting good electircal contact, but the unit is a bit jerky at slow speed, has this mid-range area where more juice doesn't really change the speed, and then when you really crank the electricity up, it runs better.  My guess is something is binding somewhere in the trucks, but I can't be sure.

 Any other thoughts?

 

Oh, and I mislabeled my units.  They are in fact SD70Is, not 75Is.  I'm sure the 70/75 is an identical mechanism, but figured I'd correct myself anyways.  Laughing



Fri, 03/28/2008 - 11:35

siderod
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Bob,I was waiting for

Bob,

I was waiting for someone to bring up the 70/75 debate. The only real way to settle this is to know the road numbers of the locomotives your working on? Athearn dropped the ball in labeling the cases when these first came out.

 Glad to hear, though, that you've had at least semi-positive results! Try either PearlDrops tooth polish, or one of the automotive shops pumice-enhanced hand cleaners, and I think you'll find a fair bit of that binding and gear noise goes away.

AR 


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Fri, 03/28/2008 - 11:44

Bob
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 Joined: 2008-01-11
Cleaning Process?

Do you just force some into the trucks gearbox (or disassemble it) and run it around the tracks, or do you just push it across a table or something?  Should I reassemble the thing loaded with an abrasive and let it run for a while?  I'm a little unsure of how to go about doing this.  When I cleaned up the grease before I didn't take on the task of taking the truck gearbox apart.

And if pumice is the stuff to use, that's fantastic...Next door to the local hoppy shop is a Napa auto store.



Fri, 03/28/2008 - 13:22

Bob
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Posts: 46
 Joined: 2008-01-11
Still no luck with the Athearns

The one is running better, but still pretty bad compared to the Atlas, Intermountain, and Kato locos I have.  The other one is still a nightmare.  I have no idea what is going on with it.  I'm about ready to put them on the auction block or something.  Maybe I can take 'em back to the LHS and see if they'll let me trade in for something else.

I'm fresh out of ideas on how to fix these goons.



Fri, 04/04/2008 - 10:54

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