Slicker than Bug $#@& !!!!!

My new order of goodies for the 6773 arrived this week! I got new Cascade Green plastic handrails, and a new dog bone drive! Sorry Emma, not that kind of dog bone.

In older Athearn's, they use a spline shaft to drive to transmit the power from the motor to the trucks. The slop in that system makes for a pretty noisy ride. I ordered a new motor that takes Athearn's new Hex/Dog bone drive. This one piece design is a lot quieter, and it only took about 10 minutes to install.




After putting it back together, the difference was like day and night. True, it's still not as quiet as a Kato or Atlas, but hay, compared to the old drive train, it was well worth the money! Next up will be the new handrails and remounting the couplers with a shorter box that does not bind the trucks up.

As a wise texan once said, "That is slicker than bug S#!& !"

It's Alive!

I went to the LTS (Local Train Store) on Saturday and picked up a Digitrax DCC Decoder with the Athearn Harness.

I did a couple of things to the motor before I installed the decoder.


First, I disconnected the drive shafts and started the motor running. Then I took a file to the commutator, to clean it up an polish it a bit. You can see a bit of difference between 6773's (top picture) and another unit that is waiting to go through the shop.



Ugly nasty commutator :(


After that, I started to install the decoder. the instructions were helpfull, except for the text about the actual installation, which is for another type of wiring harness. I worked off the diagram, and this what I came up with.

1) Attach the red wires/clips to the L brackets coming out of the trucks. I did this so the pigtail end was at the rear of the loco.

2) Attach the black wire/clip to the headlight post. On mine, I had already had extracted the headlight in preparation for one that does not light up the entire cab.

3) Remove the motor from the frame

4) Cut a narrow piece of electrical tape to cover the space between the motor mounts in the frame. I didn't actually do this on mine, but I should and you should to!

5) Carefully remove the bottom motor clip, making sure that the spring and brush don't make a run for it. At this point, for a smoother running motor, you can cut off about one third of the spring. This reduces the pressure of the brush against the commmutator and let's the motor run more efficently. Attach the Gray wire/clip to the bottom of the motor.

6) Repeat step 5 with the top clip, attaching the orange wire/clip to the top of the motor.

7) Put the motor mounts back on the motor and reinsert into the frame.

8) Insert the drive shafts into each end of the motor, and place the worm end back into the truck and replace the cover.

At this point, the unit is ready for a test run. Place it on a DC powered track, and slowly increase the voltage. If the unit does not run, IMMEDIATELY remove it from the track. Make sure that your motor is fully isolated from the frame. The decoder I got, a Digitrax DH123 can tell if the motor is not isolated, and will shut it's self off. Older decoders will eventually release the magic blue smoke if they are on a non isolated motor.

My test run was a success, so I started to put it back together.
I started by running all motor and power related wires along the top of the motor and taped them down with electrical tape, making sure that they do not interfere with the drivetrain.

I then made a coil of the headlight wires (yellow, white, and blue) because I am not quite ready for the headlights yet, and a coil of violet and green wires. These last two aren't used by the DH123, but I left them in place if ever get a decoder that can use them.



I then placed the coils on top of the decoder, and placed the whole thing into the roof of the shell, and reattached the shell to the engine. I then ran the unit with the shell on. I found that it was binding up on curves, so I removed the Dynamic Brake hatch and pushed the decoder up closer to the roof of the unit, and that took care of the problem.

Now that she's running pretty good, the next step will be to pretty her up. Stay tuned!

Cleaning gears and changing wheels

Ok, so I went to the hobby shop tonight to get the new wheels, and when I got home I found that I already had a set, go figure.






Here is a picture of the disassembled truck. and a close up.

To get at the truck mechanism,

Gently remove the clip over the worm gear, (the gear connected to the motor) A small flathead screwdriver should do the trick. Remove the worm gear and set it aside. Make sure not to lose the bearing and washer at the end of the gear. On the six axle truck, there are three clips holding the truck together, two on the top, and a long one on the bottom. Gently pry these off, also with a small flathead screwdriver.

When you get the bottom one off, you will be able to remove the wheel sets. After that, the truck will split into two sides, one containing all the gears. Be carefull not to lose those gears. Like most smalll parts, they prefer their natural environments of floors and carpets, so keep a careful eye on them.

At this point, I'm changing out the wheels. The replacements that I got are NWSL 42" Nickel Silver wheels, stock #37142-4. I worked on one axle at a time to minimize losing parts. Start by removing one of the wheels from the axle. Gently pull and twist to get it off. Take the bearing off the old wheel, and place it on the axle of the new wheel. Gently push the new axle back into the gear. It is a friction fit, so there is no need to enlarge the hole. Repeat the process for the other side.


Here's the new wheels on the axle ready for reinstallation


There are a couple of things to check before we can reinstall the axle. First, check to gauge with a NMRA Standards Gauge. This will ensure that the wheels are the correct distance apart. The next thing is to check that the bearings turn freely on the axle. If you need to adjust the width to get the bearings to turn, make sure that the gauge is still correct. Repeat this process for the other axles

The next step is to make sure that the gears are free of flash and burs and other things that could bind the mechanism. Use a small file to remove any of these as necessary. On my engine, the gear box was dry, if yours has excess lubricant, this is the time to clean it out of the gears and gear box.

Assembly is the reverse of disassembly. Before I put the worm gear back in, I placed a couple of small drops of Labelle 102 oil and ran the truck back and forth a bit to work the lubricant in. I've read that you can put some Pear Drops toothpaste in the gear box to smooth the gears a bit. I'm going to see how the regular oil works before trying that.

That's it for tonight, I'm heading down the to CP Shoreham yard to check out the Christmas train.

Couplers and Drive Train dissection

Some early good news, it appears that the couplers are the correct height. I dug out my Kadee coupler gauge from the basement, and tested the couplers. Both lined up pretty nicely with the gauge. The little trip wire may need to be adjusted up, or I may just chop it off and attach a scale air hose.

I dissected the rear truck to show how it's done and what's inside. I'm going to replace the stock wheels with NWSL aftermarket parts. After I replace those, I'll lube the gear box and check the gears for flash and other rough spots.

Extreme engine makeover - Athearn edition

Since I have put a train track under the tree for Christmas, I've pulled out some older motive power to see how they still perform (or not as in this case) after a few years in storage.

This weeks contestant is BN 6773, an old school Athearn SD40-2. I put it on the tracks and............. nada.


It was in a box with a couple of other units (also ready to go through a rehab), but time has not been to kind to it. The wheels appear rusted, along with some corrosion of the L brackets coming out of the trucks. Also, the metal strip that connects the L brackets to the motor is missing.






I must have done some work on it in the past, as the couplers are mounted correctly to the body. I have vague recollections that this one never ran to well to begin with, so this should be an interesting project.

This project will have to phases. Phase one is getting the mechanicals to run well. This will include:

• Getting the wheels to the proper gauge
• Cleaning and lubing the gear boxes
• Verify correct coupler height
• Change drive line to Athearn's new hex drive
• Upgrade to DCC with new light package

Phase two will be to add details. I'm still researching how much I want to do on that one. Stay tuned, as the show will be getting underway here soon!