I’ve been meaning to repaint this old sd-45 that I hardly ever used. It runs fine and it even has a Sierra sound board in it that sounds really good but it still had the original Aristo couplers on it (I switched to Kadee) years ago. I got this from my wife for Christmas years ago and it had the Santa Fe silver and red warbonnet paint scheme. It needed a new battery for the sound system and since I had to take it apart to replace the battery I decided it was time to go all the way and do a complete makeover. It will be repainted for my CJM in the green /yellow /grey livery. I’m also switching it over to Kadee 930’s and adding L.E.D. headlites and ditchlites and walkway lites, The lites will be powered by a 9 volt battery hidden in the fuel tank . I’ve done this lighting system on a couple of my latest locomotives and like the results. The first thing I did was take it completely apart and soak the plastic parts in 91% alcahol overnite. I use a wallpaper tub to do my paint removal . Its long enough to fit all my parts in it. Here is a few shots of the progress so far.
Here’s most of the parts after a night in the bath.
I took the frame and turned it upside down and started on the Kadee conversion. I didn’t take the paint off the frame cuz I still wanted to have the cool EMD logo that Ariso put on the side so i’m gonna clean the frame with 70% alcahol and paint over the existing paint.I use eather 830’s , 930’s (brown) or better still the new 906’s. On this engine I had a set of 930’s laying around so that is what i’m using here. First thing I did was remove the original Aristo coupler mounting posts and some molded on plastic cross braces to make a nice flat surface to install a new coupler mounting pad . I will laminate some 0.80 and if needed thinner plastic to bring the coupler down to the correct height . I havent determined the permanent front to back placement of the coupler as of yet. However I temp clamped the coupler to the frame to see how the new coupler will fit when the motor blocks are mounted. I saw the coupler box was too long and so I modified it by cutting it down . The back of the box is open but i’ve done this before and it still works just fine. Since the pilots are removable it shouldn’t be too big a deal to open the pilot up to fit the 930’s through them . After I fiddle with the pilots and frame i’ll know where to mount the couplers for good. Then I will screw them through the pad ,coupler and frame with 4-40 screws . Here are a few more pictures. 
Nice pictures. That alcohol bath works great! Do you have to scrub at all, or does the paint just melt away?
No, you have to still scrub it but it comes off real easy.
are U going to lower the engine down any?
No , I think they did a good job with “this” design.
Got a little more done today. The first picture shows the coupler pad I made for the engine . It’s a laminate of 9 pieces of 0.80 plastic. I still have to build it up a little more . When I temporarilly mounted it with the trucks it still looks around 0.30 to high. The next photo shows how I opened up the pilot so the kadee box will slip in and rest on the new coupler pad. On the backside of the pilot I had to cut away the middle of it so the block would fit and also cut about 1/2" off the bottom of the pilot so I could screw the screw into the block. It lined up so I had to do that. I will be gluing the pilot to the frame and the pilot and frame to the coupler pad with MEK. Its a little trial and error on the first one till I get it right .
Urrggg. I missed telling you this, unless you already knew? The small KD coupler box fits right in the factory hole.
I need to follow this because I have the same engine all torn apart in my to do pile. I like the idea of that big block for the coupler. It seems like the stock posts could be a weak point? I would at least shim and add hot melt behind those factory ones. This block idea looks more solid.
Don’t try that alcohol soak with any LGB engine that was made in china…
The plastic turns brittle and will break even when you lift the engine out.
Trust me…been there.
Joe , I do all my engines this way. I guess I do it the hard way but i’m confident the coupler will stay on even under heavy loads. I use a 4/40 screw that goes through the coupler , pad and frame . Did you mean the small Kadee will fit through the original coupler hole in the pilot? I did finish the front coupler mounting . It took 9 0.80 shims , one 0.30 shim and one 0.40 shim to get it to match my Kadee guage. A 2" 4/40 screw fit perfectly , didn’t have to cut it . Here’s a couple of photo’s of my finished coupler mounting . 
I’ll have to look up the right number. I think it’s the 907 that has the small box? that one fits right in. Nice work though!
Yeah…I checked it out and I see your right. Oh well . I would like to see it in person so I think i’ll go and try it using the original post and a # 787 coupler. If the coupling is as close or closer than what I did then i’m sold . Why do more work the acheve the same results.
I went down to my Kadee parts drawer and I had a #787 and checked it out. It fits real nice through the pilot like you said . It would be a easy conversion however I don’t like the look of the offset as seen from the side. I think the 930 just looks better and for me worth the extra work.
Mike
another option is to use a KD 789 Ted Doskaris has a nice write up on doing this. I have done this and it has worked out well http://elmassian.com/trains/ted-doskaris-vignettes/aristo-gp40-kadee-retrofit.
Richard
Thanks Richard for the link. Ted did a nice mod there too. However I think i’ll stay with my meathod . Its easier for me to do it this way. Good to see there are other options out there.
Got the couplers mounted and now onto the paint. The first thing I wanted to do was cover up the marker lite area on the front and rear of the engine. I’m not gonna use them . I left them white in the pictures so you could see them. I used a paper punch and some 0.10 thick plastic to make these little cover plates . I used MEK to glue them to the shell . I don’t use primer as my base coat . I sprayed the Poly Scale yellow with my airbrush directly onto the plastic that was thoroughly washed before I began.Then I airbrushed where the CJM logo will go on the long hood , below the windows where the numbers will go , the frame sides where a row of stripes will go and finally both ends where the yellow stripes will be. Now i’ll let it dry overnite and then i’ll mask it for the next color witch will be green. Here’s a few more pictures of my progress. 
Covering up the marker lights on my locos is on a to do list (someday) as well. I personally like how you used the 830’s and might do that myself as I don’t like the look of the offset 787’s on my locos either. Never really considered the 830’s but I like it!
I use vinyl letters and numbers as well as thin tape to mask my locomotives for paint . Heres a few pictures of the loco with the second color airbrushed on with the vinyl paint masks removed. Now I have to get it ready for the next color which is grey. I added window shades on the cab and still want to add a radio antenna and perhaps a air conditioner on the cab roof. 
Looks amazing!