A lot of the Bachmann non-sound decoders use the NMRA/Lenz decoder functions, but there's no good direct translation from German to English (words jumble up). I was however able to get a basic CV listing on the bachmann site & what with having around 13 of these GE 70 Tonners over the years as they came out with the first DCC - No sound units, the numbers all seem to match.

The link to the PDF file for CV listing (Bachmann) is here: https://www.bachmanntrains.com/home-usa/dwg/dwgs/NEM-1LenzDecoderCVTable.pdf

The Standard NMRA CV standard listing is here: https://docs.tcsdcc.com/wiki/NMRA_Standard_CV%27s

Hope this helps.

R. Montanye
Montanye Models

If you remove the trailing truck on the locomotive, you will see a small pcb board with 2 copper tabs. These are the drive wheel pickups. HOWEVER - if your locomotive runs fine on straight DC power, the problem is the board in the tender. Double check the orientation of the 8pin decoder.

I just remotored one for a customer & had to dismantle the entire thing. So many tiny screws to get it apart. I have some pictures of it, but no way to get them on here.

R. Montanye
Montanye Models

Also -- a tender color photo can be found from the parts dept website :

https://estore.bachmanntrains.com/images/ho_parts/0AD01-PCB02.JPG

Red in the front, black in the rear.


R. Montanye
Montanye Models

The heavy & the Light Mountain DC / DCC versions had an 8pin plug in the tender. If you push too hard to install the decoder plug, the boad will touch the steel weights, causing a dead short. Also, it'll cause a dead short if you have it plugged it backwards. The #1 pin is not clearly marked on these & will cause issues exactly what you are describing.

I recently just repaired about 4 of these things for pretty much the same problem you are describing. In all the board was touching the metal weight & the plugs were installed backwards. You can use electrical tape on the weights to stop the short issues, & after you've done this, leave the tender shell off when you install your decoder. Test to see if it is shorting out. Then if it is, pull the 8pin out, flip around 180 & reinstall it - the problem should correct itself.

Good luck with the fixings.

R. Montanye
Montanye Models

If this is the regular Bachmann Blue box then your exploded diagram is here: https://www.bachmanntrains.com/home-usa/dwg/dwgs/HO_GP40.pdf

If you have the DCC Equipped - Non-sound unit, then your exploded diagram is here: https://www.bachmanntrains.com/home-usa/dwg/dwgs/HO_GP40_DCC.pdf


VT Bob

NWSL has metal gears for the Doodlebug.

Rob

UPDATE -- Yes - there are 2 hidden screws that the exploded diagrams do not show clearly. I had to remove 4 detail parts to find them, then I was able to dismantle this locomotive. I found that the running issue was a headlight wire that was pinched & had shorted out under the diecast boiler, and that the bottom plate wires were rubbed raw on the rear axle, also causing a short.

I did buy a new driveline & tender from the scratch-building parts dept a while back so all I have to do is swap the shell. But I have been asking about how to get this shell off for almost 3yrs now. I find it hard to believe that no one has taken these apart on here, or that there's no YouTube videos to point out those hidden screws. I have studied the diagrams, & while there's a very tiny mention of "A" screw on the diagrams, it's impossible to tell where it actually is.

I wish there was a way to post a photo on here without needing some sort of special account somewhere to do so. I'll try to link it from my shop page elsewhere, but I have no idea if it'll work.

https://scontent-bos5-1.xx.fbcdn.net/v/t39.30808-6/453626092_10233385446283423_2007488137013048926_n.jpg?stp=dst-jpg_p526x296&_nc_cat=100&ccb=1-7&_nc_sid=aa7b47&_nc_ohc=iBzTMxCiA7UQ7kNvgEbeaQz&_nc_ht=scontent-bos5-1.xx&gid=AzBGLLHK_lJxzjto47xHATa&oh=00_AYBz_GtKvN-pWRSoZnJAEOqNq1SRw1jBMyJGxogIRHV0WA&oe=66B0612B

Rob

I have those, but it's not very clear as to what goes where. It's almost like just a parts list all pictured on to a piece of paper. I have removed, both cab screws, the stack, the pilot. That's all I can find for screws that are visible. Is there a hidden screw somewhere?

Thanks,
Rob

Hello,

How does one get the boiler shell off? I've removed the 2 under the cab screws, and the stack screw, but it's still firmly mounted on there. Is there a screw hidden somewhere that I'm not seeing? I've heard that on the 4-6-0's there's a screw hidden under a dome, but before I go wrenching on the dome, I'd love to know what or if I'm doing anything wrong.

Thanks,
Rob

I have the 3rd generation of NYC 4-8-4, & all I need is an axle gear to make it run again -- finding the gear? Almost impossible. Went round & round with the guy from Shapeways, but his gear is for the pancake motor version - 1st gen. It does not fit this one.

Parts used to be available all over, but as time marches on, less & less of the parts are produced, because we seem to be living in a "It's broke? Throw it away & buy a new one" generation.

I'm old school -- if it breaks, fix it, but even I'm not having any luck getting parts.

Rob

Which version of the 70 Tonner do you have? They made a 2 motor & a 1 motor version over the years.

Rob

I have 2 of the Shay's - I also built a steel jig to get the new gears from NWSL on with, but just haven't bitten into that nightmare project.

I also have a 2 trk & a 3 trk Climax, while beautiful units, I should have bought brass instead. Neither plastic Climax has moved any farther then 10inches under their own power before the gears crapped out. I have some gearing for them, but even with replacing the main gear box with the bachmann replacements, those cracked as well, so I have 2 very expensive paperweights now. Probably going to place them in my 'for sale - parts units" shelf in my store over here. I'm considerably unhappy with my purchase of the plastic geared logging locomotives.

Rob

I ended up hunting down a master modeler (some years ago) that was repairing the shays, & he gave me a plan to make a steel bar jig to lightly tap the NWSL gearings on to the shaft. That's the easy part. The troublesome part is getting the drive shaft itself out of the truck without damaging the small plastic bearing caps that hold it in place.

Rob

The NWSL Shay gears are here: https://nwsl.com/products/bevel-gear-ho-bachman-2-truck-shay-81907-80-ton-3-truck-upgrade-bevel-gear-6

As for the Climax gearing, it's impossible to find all the gears needed, unless Bachmann creates more. I'm still waiting to find the drive shaft gear with the shanks. I bought my 2 & 3 truck Climax units some 10yrs ago, they moved approx 10inches & had broken gearing. Makes me wish I had bought brass instead, because I now still have 2 very expensive and broken models, with no repair in sight.

Rob

Quote from: jward on September 09, 2023, 12:24:22 PMPretty much anything the real StJ&LC ran including its successors as well, would run well on 18r. I visited the line in 1979 when it was the Lamoille Valley, and they were running RS3s at that time. Will you have a covered bridge on your layout?

I actually do. -- I built the Swanton covered bridge out of balsa wood & It's about 32inches in length. It's currently getting added to my main layout (this afternoon actually)

There's still the Fisher covered bridge in place in Wolcott VT, but they've torn up the rails & changed the outside cladding. It doesn't have the same look as it did when rail ran through it, but I have so many photographs of the line back when it was railroad.