Repowering my Athearn Loco

[Gary S.]

The flywheels from the CF7 have holes that are too big for the PPW motor shaft. Also, these flywheels don't have any plastic inserts on either end. The hex shape on the driveshaft fits directly into the flywheel.

The flywheels from the PPW motor have a hole with a plastic insert where a drive shaft will attach. Unfortunately, the hex drive shaft I have is incompatible.

I'm going to take the entire mess over to the LHS and see what other parts I can get to make it all work.

 

[diesel]

Gary, if theres nothing they can do,... ( I love a good kitbash )


use the ppw motor and flywheels, use/get older athearn splines cut them and use the fish tube trick to couple up to the newer style athearn spline. It's a frankenstein, you'll void your warrantee, but if you choose to accept this crazy idea, you'll be happy.

I on the other hand am going to buy an Athearn -9 (newest version) because the LHS I just got back from here in the city; only guy who has a Kato -9 left -in BNSF H I or H II has raised the price from $149.99 to $189.99.

HUH? usually the price goes down. This 'guy' (anyone know who I'm talking about) does this all the time, and with all kinds of stuff. If you guys think I should name the LHS I speak of let me know.

Dan
-just a little bit tiffed

 

[Gary S.]

Dan, thanks for your advice. I intend to do exactly what you said there, I just need to get the old style drive shafts. I'm not worried about the warranty, so any hacking and bashing is fair game.

Now to take this thread in an alternate direction:

Is it even possible to have an Athearn CF7 that runs as silky smooth as an Atlas Master Series Geep? What is it going to take to accomplish this? Will the Athearn trucks be as quiet as the Atlas trucks? Would changing the wheels out to an aftermarket set help?

 

[MilesWestern]

I would say maybe...I think it would if you go into the gear towers and search and destroy any flash on the gears you might see. I suppose if you really wanted to get into it, you could maybe replace the athear with the atlas, but there's throwing money at "something that ain't broke."

 

[diesel]

Well, no.... it's not gonna run as smooth as the Atlas - especially if it's an atlas from the last 2 years. It will run smoother than it does now..., and if you find the right plastic safe grease you will significantly 'quite' the run by greasing the gear boxes. BUT more than a drop of grease will attract dust, lint ect. I think thats the only reason that you wouldn't use too much grease, anyone know any other reason. (does it put a drag on the motor?)

I wouldn't try to adapt Atlas trucks. It's major surgeory and will lead to a project that may never get done. IF you do want to go that route, I would get the whole Atlas frame, trucks and motor of similar size (again u may have to cut), you'll have to adapt the body to the frame. Actually I wouldn't do that either.

Post pics if you try any of our suggestions

Dan

 

[Gary S.]

I'm hoping to get to the LHS today to get some old style drive shafts, some NWSL replacement wheelsets and grease. I'll put the PPW motor in and see how she goes.

I'm going to give this a go, to heck with the cost and effort, I am using this as a learning experience.

 

[Nomad]

Gary, remember when you regeared that Athearn and I told you to get the power trucks to where you could move them by pushing with a finger only with no drag? If you do that with those you should reduce about 90% of the noise. You will get rid of all the binding and gear clash that causes the noise to begin with.

Loren

 

[doctorwayne]

I know that you've already got a replacement motor, but reducing the endplay in the original Athearn motor will also help it to run quieter and improve its performance, especially when running down a grade. NWSL has shim washers in various thicknesses to accomplish this.

Wayne

 

[brakie]

Your best bet would have been to use a Kato motor or a Genesis motor.
I have six CF7s and all run as smooth as my Atlas locos.

 

[Gary S.]

I'm back from the LHS. Got the driveshafts, NWSL wheels, and grease. I also found some bushings which may allow me to put the original Athearn flywheels on the PPW motor.

Brakie, I have three CF7s, I'll see what happens with this one and the PPW motor. If it is not satisfactory, I'll try other options.

Loren, I'm going back into the trucks tonight to make sure everything is perfect. Right now, I'm thinking the noise is actually from the motor or the driveshaft u-joints, or maybe in the worm gear. Most likely, all of the above!

Wayne, there is indeed some play in the armature. It will move back and forth along the length of the motor. So you pull a flywheel off, then take the motor apart, and put the shims in? Do you think I could use Kadee fiber washers for this? They probably should be brass?

 

[diesel]

NO WAY!!! you found those sleeves that allow you to use the athearn flywheels! I always intended to get some of those but just went with the ppw flywheels in the end, cool, let us know if they fit.

IMPORTANTE!!! Don't take the motor completely apart if you try that.... if you undo the magnets the motor will loose that magical factory strength... it'll still work but won't be quite as strong.

 

[doctorwayne]

To add the thrust washers to the Athearn motor, remove the flywheel, and then remove one end of the motor - don't disassemble it further. Depending on the amount of endplay, you can put the washers in either or both ends. Fibre washers could end up putting "fibre fuzz" onto the commutator as they wear: brass might be better, although I believe that the NWSL ones are steel.

Wayne

 

[Russ Bellinis]

Gary, a trick I use with Athearn gear boxes to make them run smooth is as follows. First disassemble the trucks and remove any flash you might find on the gears and clean the parts thoroughly in alcohol. Then after the gears are free of flash, cleaned, and dry, I put reassemble the gearbox and put in tooth paste instead of lube. Run the locomotive forward and reverse for 5-10 minutes, or until it gets smooth and quiet. Toothpaste is the finest abrasive you can get and it will give you the finest fit for the gears in the Athearn gearbox. After you finish lapping the gears in with the toothpaste, disassemble and clean everything in the gear box as well as the housings and the brass worm gear with alcohol, reassemble the gearboxes, and lube them with a plastic compatible grease.

 

[thaddeusthudpucker]

I saw one site that talked about building your own engine, and it had the whole old engine broken down to base parts.

do have an address for that site? I would love to get my hands on it, I have been researching building my own engines. $150 for a decent locomotive doesnt quite fit my budget anymore...

 

[Gary S.]

Follow up:

Over the weekend, I worked on 2 of the Athearn CF7s and an Athearn GP35. I took them completely apart, cleaned everything, then put them back together piece by piece. As each piece was added, I ran the loco off a DC power supply, just to see where all the noise was coming from. There wasn't any single piece that was glaringly noisy. So, after assembling the chassis, I let the loco run at full speed for awhile on the workbench. I didn't put the locos on the track, I set them on a towel and hooked wires from the DC supply directly to the motor. Ran both directions, plus swiveled the trucks around and such. Then I put some pc grease in the gearboxes, reconnected the decoders, put on the shells, and put them on the layout. Well, happily, they ran okay and were fairly quiet, especially at the low speeds that they will be run at.

So I am back to being happy with them!:mrgreen:

One thing: The GP35 definitely had an issue before I took it apart. It would randomly GROWL horribly from time to time. What I am thinking is that somehow the plastic ends on the motor which hold the bushings were misaligned. The holes in the chassis where the plastic motor clips go down through were somewhat undersized, and the motor was sitting crooked. I widened them out some, and it made a better fit. These are the plastic clips that use screws to hold them to the frame.

Tonight, I will rebuild the remaining CF7 with the PPW motor just to see how she goes.

 

[thaddeusthudpucker]

LOL, talk about brushing the Gear's teeth!!!!

 

[diesel]

yes, if you've never done this the paste that was always used was pearldrops. very abrasive as far as toothpaste goes,... don't think they make it because of that. In any case for the old blue box diesels this was a way to save about three years of constant running until the gears wore in themselves, which is actually not as good in any case, wear and tear you know.... ah those blue boxes,.... blast eh?

LOL, talk about brushing the Gear's teeth!!!!