# Used Atlas GP38-2 cleanup/restore/fix + review



## Overkast (Jan 16, 2015)

So I just purchased my first used loco from an eBay auction (luckily from a local hobby shop, so I was able to pick up w/o shipping fees). It's an Atlas GP38-2 in the New England Central Railroad paint scheme, for my New England-themed trainset. The loco came with a DCC decoder already installed and ready-to-run. 


























NECR is one of the top freight roads on my trainset list, but I think it's a discontinued road theme, so it's pretty rare to come across. As such, I speculate it will be hard to find the NECR as a new loco anywhere, and thus decided to take the risk and buy one used.

I am only 3 years into this hobby so I am still learning much, but I started preparing myself for getting a used loco by first researching this particular Atlas model on Spookshow.net. It got an "A" rating on Spookshow, but the page was helpful in preparing me that I could also end up with an "occasional" model that makes a lot of noise, and so I had to be prepared to troubleshoot that.

Additionally, I educated myself on cleaning techniques to help prepare me for cracking open the motor chassis and handling / cleaning the inner chassis and motor parts for the first time, so I felt confident to do the job. I found Don Martin's 3-part video series on YouTube showing a start-to-finish process of completely disassembling, cleaning, and re-building an EMD S9, and that series was *paramount* for me in this entire process. I don't know if he's here on this forum, but a huge shout-out goes out to Don wherever he may roam  




*Initial Testing*
After bidding and winning the auction I picked up the loco at the store, took it home, programmed it on the track, and tested it. Not great  This loco was loud as hell - made a major vibrating noise as the motor spun, and also the speed pickup is slow. I couldn't get the thing moving well until it hit 30+ MPH on my Power Cab. Looks like I indeed had attained one of those "occasional" noisy models, but it was not the squealing type of noise (as highlighted by the Ron Bearden fix, which includes altering the worm shaft to remove an inner bearing block). This was just loud vibration!

*More research*
Having already educating myself on the Ron Bearden fix for squealing but knowing this was not a squealing issue, I hit the research again looking to see if anyone else was experiencing loud vibration noise, and if there was a fix for it. Results were sparse - I found one video review on the GP38-2 where a guy noted the slow speed issue, but no mention about vibration. I only found 2 forum posts where other guys had mentioned vibration, but no official consensus on the fix. There was much speculation in the comments that cleaning the motor parts of excess grease could help, so before hitting the Ron Bearden fix I attempted at a thorough cleaning first per the Don Martin video series...

*Disassembly and Cleaning*
Took off the shell, and took note of all the parts how they're put together for re-assembly:

















Finally got the chassis open, and discovered a lot of excess grease inside the chassis and all over the worm gear parts:








Executed the Don Martin cleaning steps verbatim from here...

*Re-testing*
During re-testing, I encountered some rookie mistakes that I had to troubleshoot. The first issue was when I turned the power on, the loco started going on it's own and only in one direction, and I couldn't stop it. If I hit the "reverse direction" button it would short the system. Clearly I messed something up when I put the chassis back together. I already had a hunch it was the motor contacts that touch the decoder, but it took some trial and error (and more research on factory install of the board) to discover the problem. One of the motor contacts was touching the chassis frame and shorting out! Per the factory install instructions, there should have been some kapton tape applied to insulate the motor contacts from the chassis frame, but no one had done that. So I applied some myself:









I put it back together, got it on the track, and voila! The kapton tape worked, as the loco worked fine again . I put the shell back on and started to run the loco to test it's response from cleaning...

Well, the cleaning only slightly improved the speed pickup issue but not much - I believe this is just an inherent style of this model. Spookshow does mention the slow speed of the engine with a reviewer praising this, so perhaps it's just a protoypical thing I'm not used to yet (having only run a Kato F40PH to date). But the cleaning did seem to moderately fix some of the vibration noise, albeit not completely eliminate it. So I was still not 100% a happy camper just yet...

*New issues arise*
Attempting to troubleshoot the vibration noise, I removed the shell again to run the loco as just a chassis on wheels to see if the shell was creating the noise. I put it on the track, and suddenly could not get the loco to move! *WTF!!! It was JUST working*  I could get the headlights working but the motor wouldn't run, so it was not shorting and it was not a decoder issue... it was a motor issue.

After tearing apart the chassis again to inspect more, I saw nothing. Re-built and put it on the track and it worked!!! WTF!!! Something's not right obviously. So I left the motor running in super slow speed and attempted to handle it while on the track. Well, low and behold I discovered that the motor is not super-snug in the chassis, and a subtle shift to the right and the motor would just stop. I also noticed a slight "click" when this shift would happen, and that click was providing an ever-so-slight resistance, to the point where my finger had to actually push the motor to get it to shift, so at least there was hope that the motor wouldn't shift on it's own during operation.

Still though, I don't want to have to deal with this issue for the long term, so I decided I needed to either improvise a fix or return the unit (which I really didn't want to do, I want this NECR road on my layout!).

*Toothpick modification - the miracle fix!!!*
I needed to create a "wedge" to insert into the motor area to keep it in one place w/o the possibility of ever shifting on it's own. Also needed something non-conductive. A toothpick seemed to be the best choice here, so I put the chassis on the track and inserted a toothpick in various spots and ran motor tests until I found a spot the toothpick was both snug and the motor wouldn't move w/o a lot of finger-push force.

Wouldn't you know it - not only did I find the right spot, but the toothpick also completely eliminated the vibration noise issues of the loco as well!!!!  Hallelujah!!!! 









I now have a super-smooth and *quiet* running locomotive as a wonderful addition to my New England-themed layout!

*Final thoughts*
Spookshow rated these locos an "A", and perhaps (and hopefully) they are in fact an "A" in terms of operation reliability. Time will tell. But from my research on vibration / noise issues and the discovery of a toothpick being the magic solution to a silent and smooth-running motor, I have to say the chassis design on the Atlas GP38/40 gets a "C" at best!!!


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## irontodd (Aug 28, 2014)

nice job! thanks for sharing


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## flyingtomg (May 7, 2013)

That was a good report. Thorough, illustrated, and well written. Thanks!


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## Overkast (Jan 16, 2015)

You're welcome!

Sent from my SM-N910V using Tapatalk


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## Tony35 (Mar 18, 2016)

I just picked up 2 GP38s from Atlas's latest run
To say they were just a bit over lubed is an understatement 
The gear tower was just packed with grease


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## Overkast (Jan 16, 2015)

Tony35 said:


> I just picked up 2 GP38s from Atlas's latest run
> To say they were just a bit over lubed is an understatement
> The gear tower was just packed with grease


I'm not surprised to hear that Tony... I've heard that some people, the first thing they do when they buy a new loco is disassemble it and clean it to remove all that excess grease from the factory assembly, and give it a proper lubricating oil instead. That video series from Don Martin in my above post is incredibly helpful if you're a n00b (like me) at disassembly and cleaning!


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## Tony35 (Mar 18, 2016)

Never had to do it to a Kato or FVM
But it was really no big deal had to install the decoder anyway so as long as I was in there clean her up


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