Repowering my Athearn Loco

Discussion in 'HO Scale Model Trains' started by Gary S., Nov 28, 2007.

  1. Gary S.

    Gary S. Senior Member

    Well, originally I was happy with my Athearn CF-7s, but then I went and bought an Atlas Master Seires U23B. And geez, that thing runs smooth as silk, and the Athearns now seem noisy and rough with poor low-end speed control. Just to see where the problem was, I removed the universal joints from a CF-7. I then placed it on the track and ran just the motor. Well, the motor is very noisy. I put a little LaBelle oil on the bearings, but it didn't change anything.

    I think I want to repower the loco with a good can motor. I did some research, but want to ask if any of you have done a remotor job before. What motor would you recommend, etc?
  2. DeckRoid

    DeckRoid Member

    I had 2 Athearns that ran silky smooth and 2 Athearns that ran noisy and rough. I thought I would just swap shells, but the 2 that ran smooth were the silver Sante Fe and the 2 I wanted were black NP. So, I had to swapped motors. Fixed the issue and now I have two very smooth running NPs.

    This probably doesn't help, seeing as how I used almost the same motor from the same company. The originals had larger brass cams, but I haven't seen any decrease in power yet. I can still pull all 24 cars.


    PS - what is a can motor?
  3. bigsteel

    bigsteel Call me Mr.Tinkertrain

    i have only one athearn thats pretty darn old by its looks.its a C&O GP-9 that i think was custom painted but for 10 bucks it was worth it :mrgreen:.but is pretty noisy and didn't notice till i got a proto 2000 GP-9 that the athearn is over sized !?!? :confused:.just from looking at it its like a scale 4in taller and 4in wider :eek:.but I'm going to keep it just because I've got a Stewart drive that might fit and i don't think it'll be noticeable to others 3ft away :mrgreen:,besides,i don't think its worth it yet as i don't have many engines anyway.--josh
  4. Gary S.

    Gary S. Senior Member

    All the repowering kits I found online are actually for the older Athearn Blue boxes. The newer stuff like the CF-7 has slightly different u-joint components and the flywheels and shaft size are different. The CF-7 shells are actually accurate and look good, I just wish the drive was better.
  5. DeckRoid

    DeckRoid Member

    Which kind of Athearn connector? Are these the old Athearn or new-ish Athearn connectors?

    Choo Choo.jpg
  6. Gary S.

    Gary S. Senior Member

    The CF-7 has the "B" drive.
  7. Nomad

    Nomad Active Member

    Gary, a long time ago I remotored an Athearn using a motor from an Atlas. Worked good to. I used fuel line that's used in gas powered models for the u-joints and drive shafts. I also used double sided foam tape for the motor mount. Could that work in your case?

  8. Gary S.

    Gary S. Senior Member

    Loren, that would probably work if I can't find anything else. Right now, I am looking at an article in an old MRR mag. It has info about a CF7 built form a RailPower Products CF7 shell with an Overland Models chassis and drive. I'm not familiar with Overland Models. Anyone know about their drives?
  9. Gary S.

    Gary S. Senior Member

    Well, nix on the Overland chassis and drive, seems they haven't made that for years.
  10. doctorwayne

    doctorwayne Active Member

    Remotoring Athearns is pretty easy. I've done a couple of geeps, several switchers, and some U-boats.
    I use either Mashima or Sagami can motors: I got my Sagami through NorthWest Short Line, and the Mashimas at the LHS. If you intend to do any amount of remotorings, the NWSL catalogue is well worth the cost. Not only does it contain listing for motors, gears and driveshafts, but there's also lots of tips on doing remotoring jobs for various locos. Their motor listings contain spec sheets for all of their motors, giving all of the motor's dimensions, along with its rpm and horsepower. :eek: In general, pick the slowest running motor that will fit into the space available in your loco. In most cases, it's better to go with a moderately-sized motor, then add some extra weight in the left-over empty space. Most of these motors can handle far more weight than you could ever be able to cram into the shell.
    Ideally, the drive train should be as straight as possible, so you may have to modify the frame in order for the motor to sit lower. Another alternative is to use a flat-sided can motor, and mount the motor on-the-flat.
    Different motors may have different shaft diameters, and none of them may match the driveshafts in your loco. NWSL offers brass bushings in various lengths, and various inside and outside diameters, and these can be used to match the motor's shafts to the drive train of almost any model.
    I don't have an awful lot of motor pictures, but here's a Mashima flat can motor mounted in an Athearn switcher.

    If I recall correctly, I had to remove only a minor amount of material from the underframe in order to allow the motor to sit level. The motor is held in place with silicone caulk. Those adapter bushings are a press fit on the motor shafts, then the Athearn drive component presses onto that. I believe that I may have had to shorten the drive shafts a bit, easily done with a utility knife. I also omitted the flywheels, as I don't feel that their small mass has much effect on running characteristics.
    You can see the brass adapter bushing in this view, between the main body and the ball of the male drive shaft component.

    Here's one of the U-boats - the motors sit almost too low.


    While these locos are extremely powerful, I believe that they might have been even moreso with only one motor, but more weight. Total loco weight is about 33 ounces. ;)

    My friend Deano has the U-boats, as they were too modern for my '30s-era layout. And while the switchers are also too modern, I occasionally run '50s-era, and these locos run extremely well, either with one another or teamed up with any of my steam locos.

  11. Dr. John

    Dr. John Member

    Awesome stuff there, Doctor Wayne! I bet those U-boats could pull quite a train!

    Does A-Line still make a repower kit for Athearn?
  12. green_elite_cab

    green_elite_cab Keep It Moving!

    It sure does! I used their U-boat kits for my E60MA and E60CH. The motor runs silent, but i think my drive is making alot of nose. I suspect the shaft is to short, and is moving around alittle. the gears in the trucks may also be a problem. Then again, i've barely run them (decoder trouble), so maybe they need to get broken in. Here is a picture. everything except the frame and the truck clips are brand new from A-line/Proto Power West. they are pretty good in parts

  13. Russ Bellinis

    Russ Bellinis Active Member

    GEC your problem is that the motor is not sitting level in the frame. The end nearest us looks to be raised and the far end lowered in relation to the trucks. For smooth operation, you want to have a dead straight center line in all planes from the front of the front truck to the back of the rear truck when the locomotive is sitting on a straight level track. That will allow the trucks to move around to compensate for dips or bumps without disrupting or binding the driveline.

    Gary you can get the can motors from Northwest Shortline or from A-line. Check your Athearn motor's commutators for carbon build up. If the commutator is black with carbon, that might be your problem. You can clean off the carbon by running the motor with the drive shafts removed so the wheels don't turn. Then you put the eraser end of a #2 pencil lightly against the commutator until it is shiny brass. Take a small flat blade precision screw driver and use the point like a knife to cleanout the grooves between the bars on the commutator. It is not as bad a problem in the new Cf7 because Athearn now uses screws through holes in the bottom of the frame to fasten the motor mounts down securely. In the older Athearn drives with the friction fit nylon motor mount, the mount would tend to pop out of the frame in transit and the motor would vibrate against the body making a lot of noise.
  14. green_elite_cab

    green_elite_cab Keep It Moving!

    It is mounted straight, that was an old picture with everything loosely fitted together. I noticed that it is tilted in the photo, but i used those mounting pads to mount it straight. I will try and adjust it better though, to see what happens.
  15. Glen Haasdyk

    Glen Haasdyk Active Member

    Ah, the Old Athearn Growl. I grew up with that sound. I've still got two GP-7s that I run ocasionally so my wife knows where I am in the house.

    One area of noise creation is the plastic clip that holds the worm in each truck. Often there is a small piece if plastic flash that can cause a bind by contacting either the worm or its shaft.
  16. diesel

    diesel Member

    hey Gary,

    Check to see if the CF-7's motor has a 2 mm shaft into the flywheels. (thickness) if it does, you won't have to replace the flywheels, or worry about drive link problems. You also have a choice of motor you want to use:

    1. Mashima (proto power west many favored)
    2. old sagami; if you can find one -make sure of fit
    3. new sagami; he actually wanted to start making motors again; again if you can find them
    4. north west shoreline: based on the old sagami but even smoother if you can believe that
    5. Kato's project motor: IT'S ONLY $19.95! - i have one and it runs as smooth as the others.
    6. find either an Atlas or Kato motor (regular stock) and make that work.

    Repowering can be easy, But, you have to work to make it fit the way you want.
    AND Definitly make sure the motor fits before you buy Especially with the older Sagami if you go that route.


    I had the same problem with the splines being too short after the motor was in. What I did was cut the spline in half, and then used tubing from a fish tank filter ($2.99 for a yard at the fish store) and use that in between as an extender. Also what I did to quite the noise was use vaseline like grease in each of the fittings: smoooooth

  17. Gary S.

    Gary S. Senior Member

    Thanks for all the comments so far, gentlemen. The LHS had a Proto Power West motor with flywheels. I bought that, but now have discovered that the flywheels are not compatible with my drive train. And the holes in the flywheels on the Athearn motor are too big to fit the PPW motor shaft.

    As in the pic below, my drivehaft has the hexagonal end as in B, but the PPW flywheel has a hole with some plastic "cog" type arrangement in it, I assume this is for an older version of the Athearn drive shaft.

    So to sum up... my Athearn flywheels will not fit the new motor. The new flywheels will not fit my driveshafts.
  18. DeckRoid

    DeckRoid Member

    Can you swap out the brass ends? Replace the motor but keep the brass flywheel that connects to the motor? Anyone out there done such a thing?

    I saw one site that talked about building your own engine, and it had the whole old engine broken down to base parts. I don't know how one would go about removing the flywheel, but it might be an option.

    Sorry if this doesn't help.

  19. diesel

    diesel Member

    Not to worry, actually yes I did forget... a Proto motor is also a good choice.

    first of all when doing this don't throw anything away just yet....

    anyway... look at the ends of the fly wheels where the black plastic is.... you can take a pair of needlenose plyers and pull those out. go to the athearn motor you are replacing and find a way to get those fittings out as well. then... pop them in the proto motor. If you got a motor with very short flywheels or if for whatever reason the splines don't reach.... use the fish tube or some similar trick; OR

    if you want to forgo the newer athearn splines altoghter (because they're too thin and loose torque) find a way to use an older athearn spline system. As mentioned before, thick plastic safe grease will keep this mechanism quite.

  20. diesel

    diesel Member

    oh i thought u meant a proto 2000 motor anyway... above still applies.

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