New Rehab Project- Old GP9 AHM?

[cedarwoodron]

Among the many orphans I have allowed to come into my collection from nefarious swap meet and flea market origins, is what I believe to be an AHM/ Mehano GP-9, in GN colors. I say "believe" as it has the famous " made in Yugoslavia" mark on the bottom of the chassis. I then came across the "re-vitalized" IHC of Texas website, and saw that they have an SD-24? which has a shell that looks virtually identical (with very few cosmetic differences) to this old GP-9 I have, despite that mine is a 4 wheel truck and the IHC offering is 6 wheel. Has anyone tried to clean one of these old units up, or repowered one? Cedarwoodron

[dknelson]

AHM, more or less the predecessor to IHC, had a GP18 in their catalog and it not only generally looked like a GP9 in outline (there are of course spotting differences) but they had it in GN paint

The HO Seeker website shows the engine and the catalog number:

http://hoseeker.net/ahminformation/ahmcatalog1973pg19.jpg

My hunch is that is what you have, and if so it is not at all the IHC SD24.   The AHM GP18 shell had decent detail for its era (indeed once you strip the thick paint off it is impressive how much detail they managed to mold into the shell) but the huge railings and stanchions, the quiet but jerky mechanism, and the truck mounted couplers and toy train pilots count against it.  Moreover the distinctive body/frame/chassis construction makes it a challenge to repower or move the body over to a different power chassis.

If you have older issues the model was reviewed in the December 1977 issue of Railroad Model Craftsman (seems like yesterday

Dave Nelson

[cedarwoodron]

Thanks Dave- I will do more research, as you suggest, but perhaps just a good cleanup might be in order, as the internals don't look that bad ( perhaps someone got there before me ), either way, there is some satisfaction to be gained by a frugal refresh of this model, as an experience project, if nothing more. Cedarwoodron

[Doughless]

I bought a new one of those locomotives when I was a kid.  It was in GN green and orange paint and was labeled a GP18.  Also owned the BN version. I remember buying it from the Woolco toy department in the late 70's, probably for no more than $15.  In fact, when I sold off many of the older collection I saved this GP18's shell because I also thought the shell had pretty nice detail, and may attempt to place it on a diffrerent chassis some day.

Admittedly, I tend to be a slow speed snob when it comes to judging locomotives, and the AHM power chassis fails to measure up.  I do remember, as a kid, that locomotive seemed to win all of the drag races it had with the few other locomotives I owned, when using my old TYCO power pack.    

I remember it ran quieter than the two Athearn BB's I had.  I wonder if that old GP18 would run much better today if supplied with more modern electronics.

[Darth Santa Fe]

The GP and SD diesels look very similar to eachother, but SDs are longer than GPs. If you look closely, you'll notice that the SD24 has one more radiator fan on top than the GP18.

I've cleaned up older engines with the same motor and trucks as your GP18. They usually run pretty well when their condition is kept up, but traction tire equipped models may have a noticable wobble to them. These also sometimes have poor electrical pickup, so adding wipers to the rest of the wheels can improve performance.

[cedarwoodron]

Thanks Darth- with help on the forum, I also finally came to the conclusion that I have a GP-18 from AHM. The previous owner was nice enough to put Kadees on the truck-mounted coupler housings, so I guess I will settle for some good old fashioned inexpensive, yet strangely soul-satisfying internal and external cleanup of the drive and a little LED magic for the lighting. That GN goat is the old 1930s caricature drawn, so I might try to replace that with a real 1950s updated herald decal, but as long as it runs, it can be a charmer on the back tracks of my humble layout. AntonioFP45 ( my workplace pal) suggested a light dish soap and water cleaning to get the griminess off the paint job, and I am guessing there can be some detailing and painting done to the lower fuel tanks and trucks to improve realism a bit. Cedarwoodron

[last mountain & eastern hogger]

I have that same unit only in Western Pacific orange & Silver.  I bought it in Rochester, Minnesota about 30 years ago.  It is AHM and this one came with one powered and one a dummy, in a long box.

I still have them, but they don't get much use.  It was a speed demon and now it is quite intermittant.  See how you make out and let us know on the refurb.  It might prompt me to see if these too can be saved from shelf queen status.

Johnboy out............................and wondering where those thirty years have gone.

[cedarwoodron]

Thirty years ago I WAS in Minnesota, going to college and happily buying train stuff at Woodcraft on Lake St, Gagers in Southdale,etc. You are right, though, where did the years go? My one shot at improving the slow speed ability of this old dog might be to see if I can replace the worm or worms with a single lead one, to reduce the gear ratio of the gear mechanisms. But I will let folks know what is new on this one as the project unfolds. Cedarwoodron

[cedarwoodron]

I finally got around to that old AHM GP18 and managed to successfully repower it (or rather, power it, as the old motor was dead) with a motor from the old Hobbytown of Boston owner, Howard Mosely, who sells the motors on EBay. They are Igarashi 18mm x 33mm flat can dual shaft motors. The only adjustment needed was to cut about 1/16 inch off each shaft, so the existing drive trains would fit, and a little creative carving to enable the bottom lead to seat in the engine cradle. I left the original front bulb in place, as it was set into a plastic housing, and added a reverse LED light for the other end, reversing the wiring to allow it to work in reverse motion. That new motor is quiet and smooth, also having set it in the cradle with foam tape to cushion any vibration. A little paint on the too-shiny deck, fuel tank and trucks and she's good to go. With that new motor, very good slow motion for freight yard use and good speed for mainline runs. My total investment was about $12.00 for the 4 motors I bought plus standard shipping, so each motor was $3.00 net. As I paid only $5.00 for this flea market antique, not a bad price overall! Cedarwoodron

[Lonnie Utah]

Kinda hate to bump an old thread, but I'm doing this exact rehab project on a thrift store find ($20 for 14 rolling stock and 4 locos.) While the shell of the 1776 seaboard GP-18 is in good shape, the motor was dead. I've ordered a very cheap ($3) dual drive shaft Nichibo can motor but the dimensions are slightly different than the original can motor that was in there. My only question to those of you that have done this is how do I mount the new motor on the frame?  I'm sure the existing motor retaining clip isn't going to fit. I'm also going to chip the loco while I'm at it. 

And yes, I know the time/$/Effort likely isn't worth the result. That's not the point of doing it. It's more of a "can I figure it out" sort of thing.  The train will become my 5 y/o's and while he's great with the layout, dad also doesn't want to have to worry about him wrecking a $250 sound loco. :)  

Anyway, thanks in advance for any replies. 

[ggnlars]

I repair these all the time.  Motors can be dead.  Often, it is sludge on the brush contact.  I think they get poor lubricant in the wrong place.  Brushes do not need lubricant.  Cleaning the contact surface is usually enough. They made two very similar units.  The first was a GP18 the other was an Alco RS11.  Chassis, shell, and truck side games were unique.  All the rest were identical.  

[Lonnie Utah]

So when I pulled the motor out and tested it, I cannot get any continunity across the contacts with the my meter. 

[dknelson]

Lonnie Utah

Kinda hate to bump an old thread, but I'm doing this exact rehab project on a thrift store find ($20 for 14 rolling stock and 4 locos.) While the shell of the 1776 seaboard GP-18 is in good shape, the motor was dead. I've ordered a very cheap ($3) dual drive shaft Nichibo can motor but the dimensions are slightly different than the original can motor that was in there. My only question to those of you that have done this is how do I mount the new motor on the frame?  I'm sure the existing motor retaining clip isn't going to fit. I'm also going to chip the loco while I'm at it. 

I found a thread on the Tyco forums where a guy did the same basic conversion and he used double sided tape, which I know a lot of guys used early in DCC when they needed to isolate Athearn motors from the frame.  I assume there are brands of double sided tape strong enough to withstand the fairly modest torque a motor of this size would develop, assuming an otherwise smooth running chassis.

I have some recollection that linking to another forum violates some rule or other so I will not provide the link, but a Google search for this term should find it right away:   Previous Topic: AHM GP18 Repower Project - Tyco Trains

Dave Nelson

[ggnlars]

Lonnie Utah

the sludge breaks the contact, thus there will be no continunity.  If you can clean it off, then it will likely run.  It could be dead for other reasons.   

If your going to replace the motor, any place where double sided tape might work silicone chalk will work.  The only reason for the tape was to isolate the motor, not to provide a strong mount.  

if your using the plastic AHM chassis, isolation is not needed.  

[Lonnie Utah]

Thanks for the google search terms Dave. I had actucally already seen that article, but missed the part about the double stick tape. Ironically enough, that was the thread that led me around the web to jameco, where I ended up buying the motors.  Funny how the internet works! :) 

& Larry, since I'm a scientist by training, I tried applying my limited knowledge of organic chemistry last night a applied a few drops of 91% isopropol alcohol to the contact to try and disolve the sluge (my thinking was it was a build up of the hydrocarbon based lubricants on the motor and the alcohol should dissolve them.)  No dice. A also noted the distict spell of "burnt ozone" from the windings before application. :( 

But a sincere thank you for trying to get me to the path of least resistance (no electrical pun intended) with this little loco. I guess it was donated for a reason.

And on a side note, some of you will think this is funny. My 5 y/o loves everything trains. He often takes my phone and watches youtube train videos on it. The other week he watched one of a bunch of CN snowplow trains blowing up snowdrifts in the heart land (it was very cool). Anyway he mentioned to me after that, "Daddy, we don't have a snow plow car on our layout...." The only reply I could think of was "Umm, buddy, it doesn't really snow on our layout." I didn't pay it much mind until I went to the Train Shoppe on Monday and saw they had an old athearn CN snowplow car in their used stock. For $10 I ended up getting it. It had horn hooks on it so I updated them to Kadees and was supposed to take it upstairs for his mom to wrap, but got messing with other projects and forgot (Adult ADD). 

Anyway when at the work bench last night (the family game table in the basement living room) he pick up the box and starts to peak in and says "Daddy, what's in this box?" I quickly replied "Don't look in there!!!". I took the box from him and said, "Did you see what was in there?" Sheepishly he looks at me and after a second says, "No Daddy. I didn't see that snowplow car...." haha. A very cute reminder of why our family has taken up this hobby. 

Thanks again all for the useful advice on this subject. I should be getting the motors tomorrow and will update this thread next week if I get a chance to work on things over the weekend. 

[Lonnie Utah]

Update: So last night during a bout with insomnia  I had some time to work on this little loco. I was able to get it working, but need to go back and iron out some kinks.  There are two main ones that jump out at me right away. The first one is easily overcome. The RMP range of the motor makes the loco run REALLY fast on the layout at full power. (FWIW, I tested it in DC mode on our DCC layout.)  If I can work out the other issues, I plan on doing a DCC conversion on this loco. So, after I get that done, I’ll simply workout a new speed table for it that will bring it down to more realistic speeds.

The second issue is related to the questions I asked earlier in the thread.  In order to get the motor in last night, I cut down drive shafts on one side so that it would link up with the drive train on the front truck. Long story short, it’s not quite short enough so it’s pushing on the front truck pushing the front wheels downward.   This is putting the front truck a little out of alignment on the track which is leading to derailments under a few circumstances (going backwards over turnouts).  This should be easily solvable under different working conditions as I didn’t want to run power tools after midnight. It also might be as simple as pressing on the spline(s) just a wee bit farther. I have a little room to do that I think. Again, I just didn’t want to go get the proper tools to try so late at night (for risk of waking up the rest of the family).  Lastly, there are a couple of inverted L shaped posts where the old motor mounted that I could trim down. This would affect the fit of the motor so I’m a little reluctant to try that method. I think all we are taking here is 1/32 – 1/16” of an inch to make it fit perfectly, so not very really.

Finally, since I still had the motor adjustments to do, I didn’t do a “final fit” of the motor on the chassis. Basically, I just shimmed the motor in along the sides of the shell using 1/8” craft foam.  Needless to say, it’s not a super sung fit, but the narrowness of the shell kept the motor from torqueing completely sideways (like it did when I was doing a shell-less test run. Well, this produces "some vibration" under the shell and makes the loco VERY noisy.  I mean like a hive of angry hornets noisy.  (The new motor I bought runs smoothly and quietly when out of the chassis so I know it's a mounting related issue) So I’m still trying to sort out the best way to securely anchor the motor to the chassis and honestly, I still haven’t mentally come up with anything I really like.  I’ve tried every think of way where I could “weld” tabs to the motor so I could screw it down, I even tired using a small zip tie through the old motor mount clip holes (didn’t work) I’m sure I’ll think of something and when I do, I’ll update this again.

Per usual, I’m always open to suggestions.

 

Later,

L

 

PS: The upgrade project on the sister loco I got with this lot (AHM Santa fe F3) went off with out a hitch. It's likely the best DCC conversion I've done to date. I had to rebuild the gear box on that one and now she runs super smooth.  Both of these will be Christmas presents from my 5 y/o. 

Edit: Here's an image of the motor I bought if that helps anyone... 

[Lonnie Utah]

Here's a youtube link to the exact loco, with a teardown and clean. 

https://www.youtube.com/watch?v=J9JdYaPtemE&t

[dknelson]

There might be ways to deaden the noise at least a bit - adhesive felt inside the shell sides so that the motor housing is touching something softer than raw plastic?  Or isn't there room to, in effect, narrow the interior of the shell?

Dave Nelson

[snjroy]

Hi there. I use silicone caulk to set the motor in place. It isolates the motor and absorbs the noise from the frame.

Simon

[Lonnie Utah]

While I slept last night, the thought "moldable putty" popped into my head, so I'll be exploring that and/or silicone as a mounting option.  Thanks again all!

Edit: So a quick google search pointed me in this direction. I think I'm going to give it a whirl and see how it goes.