Spalato68 One question: when you remove worm from gearbox, and put locomotive on tracks and gently push it forward - backward, do wheels rotate freely without any binding or hesitation? If yes, than you could assume at least that nothing has fallen inside when part of gearbox broke off. If this happened, this small piece could heavily damage gears inside and cause binding. It would be of course good if you could dissasemble the whole locomotive and inspect everything, which can be done, but is relatively complicated. If you look at the exploded diagram that you posted above, there are many parts when you unscrew the screws holding bottom lid that should be removed before wheels can be removed. So if you do it, be careful not to loose anything, especially two small springs (part 129). Also, it is good to make a photo before you remove some parts, to know how to put them back (or make sketch). Another question: after you repaired broken gearbox, did you try to put worm and clip back and try to move the locomotive (motor under power, carefully)? I just understood from your post that "worm gear is spinning" - but when? With or without worm at place? If it is spinning and worm is in its place but worm is not moving and you push drive wheels with your fingers to rotate them, that means worm gear is probably damaged. Btw - if you posted exploded diagram by yourself, than just follow the same procedure for any other picture you want to show here. Hrvoje
One question: when you remove worm from gearbox, and put locomotive on tracks and gently push it forward - backward, do wheels rotate freely without any binding or hesitation? If yes, than you could assume at least that nothing has fallen inside when part of gearbox broke off. If this happened, this small piece could heavily damage gears inside and cause binding.
It would be of course good if you could dissasemble the whole locomotive and inspect everything, which can be done, but is relatively complicated. If you look at the exploded diagram that you posted above, there are many parts when you unscrew the screws holding bottom lid that should be removed before wheels can be removed. So if you do it, be careful not to loose anything, especially two small springs (part 129). Also, it is good to make a photo before you remove some parts, to know how to put them back (or make sketch).
Another question: after you repaired broken gearbox, did you try to put worm and clip back and try to move the locomotive (motor under power, carefully)? I just understood from your post that "worm gear is spinning" - but when? With or without worm at place? If it is spinning and worm is in its place but worm is not moving and you push drive wheels with your fingers to rotate them, that means worm gear is probably damaged.
Btw - if you posted exploded diagram by yourself, than just follow the same procedure for any other picture you want to show here.
Hrvoje
The answer to question 1 is no, they do not rotate freely they partialy rotate not a full circle when I put the loco on the track, if that is what you mean.
I would like to dissasemble the loco, but the instructions on the schematic are horrible.
I have gotten as far a removing the shell, but the damn frame (89) I don't know how to remove it!
Answer to question 2, I put the worm back on and tried to move the loco with power and that's when it spinned without moving.
If the worm gear is damaged, how do you know?
To me, it looks fine, but if I take a picture and show you, then you will know better than me.
Problem is that this website makes it difficult for novices like me to post a picture.
As I said before, I have tried in the past without success, why this website insists on this method is beyond me!
These are the instructions:
Whenever someone new joins the Forums, they often have trouble figuring out how to post a photo. Here's how.
Step 1: Prepare your photo. It should be saved in JPG or GIF format, and no more than 1 megapixel in size (approx. 1000x1000 pixels).
Step 2: Upload your photo elsewhere. You can't actually post a photo in a Forum message. What you can do is post a link in your message that calls a photo posted elsewhere. So you'll have to put your photo somewhere on the Web that's publicly viewable. Many Forum members use Imgur, Flickr, or their personal websites
Think about it, I have to create a link and post it somewhere on the Web that is publicly viewable?
Why?
It would be a lot easier for one to down load photo on the computer, then copy and paste.
Anyway, it would be so much easier for everyone to understand if
1. I post picture picture of worm gear to see if it is still good or damaged
2. try and figure out how to remove the frame (89) and post pictures of gears (122) (125) (128) to see if they are still good or damaged.
Very very frustrating!!
The frustartion increases, no answer from Athearn. Not surprised!!
If I coud just figure out how to remove the frame and inspect the other gears,it would be so much easier to determine if there is damage.
But to no avail.....
Well, if wheels DO NOT rotate freely when you remove worm, that means that something inside gearbox is either damaged or moved from its position. Fact that when you install worm and use motor under power to move locomotive and it binds just proves what I wrote.
In any case, only the complete removal of wheels and dissasembly of gearbox (remove part 131), and then pull out all gears, remove all grease from gearbox and gears, inspect all and replace damaged with new one) wil lshow what happened. To do that, I am afraid it is too much for you. You managed a lot, but without a help from side (on spot, not on line), it is very difficult. It would be great if you could find some modelrailroading club near you or some modeller closer than me willing to help.
To post pictures, you must first upload them somewhere on the Internet - this forum does not offer service to upload pictures, as any other does not, only allows you to put a link to picture uploaded somewhere on the Internet. You must find some (free) service provider for that, I use German one but do not recommend it because it is in German (if you know German: link here. But there is one in English: https://postimages.org/
I am sure other members of this forum can give you good recommendation where to upload the pictures.
In any case, do not give up - find somebody who can help you nearby, because this locomotive is a beautiful piece of American railroading, and very probably, repair should not cost a fortune.
If gear(s) are broken and Athearn cannot provide them, either NWSL or some other store can help you. It is important though to know not only the teeth number, but also module (European term) or pitch (I think this is what you use in USA) and gear bore. I assume Athearn gears have 0,5 module/pitch. Such gears can be found here: https://shop.kkpmo.com/ It is store from Poland, but they ship worldwide (flatrate 6,15 Euro). There is one possible problem: worm gear (part 122) is in fact two gears in one - so if this gear is damaged, it is not easy to find exact replacement. But you can glue two different gears to make one, it is important to choose exact teeth number and of course, bore that is appropriate for that locomotive (hope it is 2 mm).
Hrvoje,
I appreciate all of your help!
With Covid and another lockdown that we have here in Ontario Canada, it will be a long, long time before I can go to a Hobby shop for help.
I took a couple of pictures of the worm gear and would like for all to see them so you can judge for yourself if they are damaged.
Again, I dont know how to post them, believe me if I knew i would.
Also, if there is someone out there who has experience in taking apart Athearn steam engines, would be greatly appreciated.
I have tried to find a video on taking apart a steam engine and there is nothing out there.
I'm going to go out on a little limb and say you should have someone here teach you the lore of making and using a quartering jig. Once you are comfortable with the operation, you will never have to be 'afraid' of drivers again, and the operation is not nearly as complicated as on the real thing (where the 90 degrees needs to be precise and so does the eccentric crank advance fof the valve gear.
Likewise taking drivers out and putting them in, and adjusting their fit, is not terrifying -- one little tip, though: practice working with the model and your hands inside something like a clear gallon-size Baggie, as when tinkering with older Kadee couplers, so the little springs don't tunnel to another dimension. Invest in a couple of good jeweler's files and other tools and get advice abd a little practice to be comfortable using them.
If the worm is just spinning without turning anything, either it is not correctly 'depthed' in its fit with the big driven gear or one (or more) of the other gears are damaged or perhaps split. This will require taking the tower out and disassembling it, which (considering you now have a 'craftsman' cover arrangement instead of a clip-on part 121) is worth learning to do.
The worm has to be removed before you can test the chassis for binding. This type of worm drive cannot be 'backdriven' without substantial damage, almost certainly to plastic gears or to 'popping' part of cover 121 or the teeth that hold it on rather than the brass worm itself. "Better" drives, like the old larger-diameter Helix Humper or multiple-thread worms, are even less amenable to backdriving.
And there is no substitute for being able to push the chassis carefully and sensitively by hand to get rid of any binding, lubrication, or gear-mesh issues. Only when everything moves smoothly is there any reason to apply high torque via the worm to see if parts move or deform improperly under load, or a cracked axle gear start to open or slip under load.
I know this is all not what you want to hear when the original option was just to eBay it out of your misery. But at this point I'd take it up as a training and learning exercise ... with the Bay still a possibility if you lose the interest.
Hello Overmod,
Thanks for you input.
I'll see if I am up to the task of trying to get to the other gears.
I was quite successful in opening the boiler and the tender, but intimidated by the rest.
I have gone over and over the schematic and it is not that easy to do.
However, I will see how it goes.
Cheers!
Th
These are two images of the worm gear.
Does it look ok to anyone or is it damaged?
To me it looks fine.
Any thoughts?
I'm not familiar with your specific model, but it looks OK to me.
Henry
COB Potomac & Northern
Shenandoah Valley
Hello Everyone,
After getting the right precision tools, I finally got the #131 gear box side plate opened to inspect the gears.
As suspected a pin that holds #125 idler gear is broken!
#122 compound gear is fine and the pin intact
#128 idler gear is fine and the pin intact
I have included a blown up drawing as well as a picture of the broken gear pin #125.
My qusetion is would I have to drill and try to insert a new pin in postition #125 or is there another alternative.
Note: Bear in mind that the #126 gear box asembly unit is no longer available as a part!
Thanks.
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With a little luck, a gear puller might free up the pin. Or, figure out if the pin can be drifted out of the hole....with drift pin.
selector With a little luck, a gear puller might free up the pin. Or, figure out if the pin can be drifted out of the hole....with drift pin.
I think that pin is not a separate part, but integral part of gearbox i.e. locomotive chassis, which is a die cast part.
Broken pin can be repaired, but this is a tricky task, with high precision requirement. First the rest of broken pin shoud be removed (grinding or similar process), and then a new hole in pin centre is required. In that hole a new pin (e.g. machined brass) could be glued (e.g. 2K glue).
I assume that on inside of gearbox lid there is a recess that was used to stabilize the old pin - if I am correct, then new pin should have equal length and have the same diameter on the side of gearbox lid.
Not an easy task - but for someone with apporiate tools and skills, it can be done.
There is also one more hope, if repair fails: Athearn has announced new run of FEF 4-8-4 locomotive, so if locomotive chasis design was not changed, it should be available as spare part.
I'd get or have access to a good small drill press -- people here will have recommendations.
I don't see a need to face off the area inside the box if you can carefully jig the broken piece so it can be drilled out precisely along the line of the pin, to the diameter of the measured fit to the hole in the gear. Then reverse and, as Hrvoje said, bore back through the hole with the cover applied.
You'll make a shaft out of suitable material -- it could probably be plastic with through-drilling, but I'd use brass or perhaps phosphor bronze if I could get it... secure the pin with a dab of thickened CA ONLY at the back end, so you can still easily get the cover off if another pin goes.
My thanks to both Spalato68 and Overmod!
I'll see if I can get a hold of a drill press and try your methods.
As far as a new chassis piece for the Loco? Athearn is owned by Horizon Hobby, I phoned them last week for assitance and I was told the service department would not be available til May 31.
I don't have much faith in them, to be honest.
Again, thank you to all!
I have one idea how to save this locomotive even if your fist attempt fails, i.e. if you do not manage to drill ne hole absolutely accurately (in the centre of former pin that is broken).
In that case, you can try this: first you have to find a workshop that can make for you new pin (brass) that is shown on sketch below - it is "mushroom" shaped (or in shape of nail with wide flat head).
Then widen hole in locomotive chasis a bit, e.g. 1 mm wider than pin width. After that you can insert mew brass pin in a way that wide head is outside of locomotive chassis. Without applying glue, you can insert gear on this pin and check if adjacent gears rotate freely whne you find "sweet spot" for new pin by moving its flat head from outside. When you are absolutely sure that new pin is fully functional and that all three gears rotate freely, you can glue it with 2k glue (5 min working time - it is enough time to again find "sweet spot"). Before applying glue, you can scratch paint from loco chassis to achieve better bond with glue. Of course, all surfaces must be absolutely free of any grease/oil. Also, be careful that glue does not penetrate on the other side, because during glueing you should use all three gears again to be absolutely sure new pin is positioned perfectly.
In case gearbox cover has recess for each pin, than you can use cover also for correct pin positioning. Again, be careful - pin should have exactly the same length as broken one.
Sorry for sketch, it is not nice, but I hope, you get the idea.
If there is no place currently in locomotive boiler (which I doubt) for pin head (1 mm thick) - make space.
Thanks Hrvoje! I will let you know how things go, again my problem here is that eveything is still in lockdown and will be till the end of the month.
There are a couple of modelers here where I live that might be able to help me. I met them last November at a model railroad club, when things were a lot better for going out. I know that one has a drill press, I talked to him today and because of covid and the fact that he is 81 years old, he does not want any contact untill the ban is lifted, hopefully in week one of June!
So, I have to wait and see for at least 2-3 weeks for any reults.
As soon as I can get his assitance, I will let you know.
Again, I appreciate your knowledge and help in this matter!
Cheers.
Hell All,
I managed to get a drill press and drilled the hole for new piece of brass 5/64 or 2mm to be inserted.
I am also adding a picture of what I have done.
Now, my question is do I use J B Weld glue to put the brass rod in the new hole or some other type of Adhisive?
Also, before I put back the gears #122, #125 and #128 do I use light oil or grease?
Thanks
I would think JB Weld would work nicely BUT be sure the fit is not too tight. Epoxy is not like cyanoacrylate 'super glue' which develops high bond strength from a very thin layer. It needs a few thou of bond line.
I presume you drilled the cover in line with the base so the new 'shaft' goes through both. You will not glue the shaft to the cover at all.
I ASSume you will put a piece of brass in the holes, apply the gears, and verify they turn correctly before you cement anything. Now is the time to make any adjustments as the epoxy is gap filling.
Put a 'collar' of JB Weld on the edge of the shaft where it will go into the hole, no wider than the thickness of the gear tower, and carefully wipe ithe adhesive with a toothpick or similar thing to make a thin layer on the inside edge of the hole you drilled. Put the shaft into the hole 'from the inside' carefully turning it a little, but only far enough to get it to be flush or project slightly, then check for any 'blob-up' at the joint between shaft and tower that might impair working of the gear -- you can smooth or remove it with a toothpick with a little corn or vegetable oil on it. Then put the cover on to line it up precisely until the epoxy sets fully, probably about 24 hours.
If you did not drill the cover, I think I would make the shaft slightly 'over length' to get a fillet of epoxy on the outside of the gear tower. We'll see if others agree with this.
Overmod I would think JB Weld would work nicely BUT be sure the fit is not too tight. Epoxy is not like cyanoacrylate 'super glue' which develops high bond strength from a very thin layer. It needs a few thou of bond line. I presume you drilled the cover in line with the base so the new 'shaft' goes through both. You will not glue the shaft to the cover at all. I ASSume you will put a piece of brass in the holes, apply the gears, and verify they turn correctly before you cement anything. Now is the time to make any adjustments as the epoxy is gap filling. Put a 'collar' of JB Weld on the edge of the shaft where it will go into the hole, no wider than the thickness of the gear tower, and carefully wipe ithe adhesive with a toothpick or similar thing to make a thin layer on the inside edge of the hole you drilled. Put the shaft into the hole 'from the inside' carefully turning it a little, but only far enough to get it to be flush or project slightly, then check for any 'blob-up' at the joint between shaft and tower that might impair working of the gear -- you can smooth or remove it with a toothpick with a little corn or vegetable oil on it. Then put the cover on to line it up precisely until the epoxy sets fully, probably about 24 hours. If you did not drill the cover, I think I would make the shaft slightly 'over length' to get a fillet of epoxy on the outside of the gear tower. We'll see if others agree with this.
Thanks for your input.
The only thing I drilled is the hole in the #125 position right through, as you can see in the picture I posted.
I already have the brass piece, correctly cut to the right size and ready to glue it in postion.
I will probably go with CA glue.
Once the brass rod is glued and ready, before I put the gears back in their respective positions #122, #125, #128, do I grease the gears with oil or somehing else?
I have always used the Labelle light grease for this -- a very little bit between the shafts and the bores of the gears, and a very little bit on the teeth. The grease provides a permanent 'thickening' that holds the lubricant on the contact surfaces. There is no need (in my opinion) to provide large gobs of grease as if this were a traction-motor gearcase, which is what you sometimes see manufacturers having done.
Others advocate using a small amount of one of the good light mechanical oils (again the Labelle line is often recommended).
Note that not all greases and oils are 'plastic-compatible' and you should check if you want to use something like green Teflon-loaded EP grease (as I have because I'd had good experience with it in other contexts).
I am SO looking forward to seeing the triumph video of this locomotive operating!
Thank you again for all your help and input.
I was on Labelle's website they have so many different types of synthetic oil.
Do I use Labelle #107 or is that for the engine axels and wheels?
Which product is the light grease # to use for palstic gears?
Hawks RuleWhich product is the light grease # to use for plastic gears?
I'd use 102 rather than 106 for the 'general' lubing of the gears and their pivots, but I think I'd put a smidge of 106 on the worm and let it work its way through on the pressure faces of the teeth. Others have different opinions on this specific application.
Here is an update on my engine.
After painstakingly taking apart the engine, checking and cleaning all the plastic gears, repairing and re-drilling one of the posts and applying the right grease on the gears, then re-asembling the engine, it was ready to be tested.
Guess what, the worm gear still spins!
Even with the cover in place, it does not stop the gear from moving up.
I am convinced that the worm gear system has flaws, because the worm gear is not broken!
The only way the engine runs is if I apply pressure on the cover that holds the worm gear.
I am attaching two photos.
The first one shows where the problem is (worm gear)
The second one shows my finger putting pressure on the cover that holds the worm gear
Obviously, this is a major flaw in the model itself.
It is of poor quality and construction. CRAP MADE IN CHINA!
I have run out of solutions!!
Help!
With the chassis on the track and the worm off, you should be able to move the locomotive by pushing the top of the gear, without stiffness or binding.
I'm still a little concerned about what snapped the pin for the second gear off... did it damage or distort the other pins, too, or the form of the gear teeth? I can't help but think someone tried to push it to make it go with the worm engaged, and all this you've been enduring is the result.
Next step is going to be to modify the top clip to be positively locked against lifting, or making a replacement worm-bearing hold down that screws or pins in position so the worm has to stay in mesh. This might be as simple as a long threaded rod through the chassis with an ear epoxied to the front of the cover and nuts to hold tension.
But I want to verify there is no binding in the geartrain, either when the chassis is pushed or when the upper gear is hand-driven, before we start there.
Overmod With the chassis on the track and the worm off, you should be able to move the locomotive by pushing the top of the gear, without stiffness or binding. I'm still a little concerned about what snapped the pin for the second gear off... did it damage or distort the other pins, too, or the form of the gear teeth? I can't help but think someone tried to push it to make it go with the worm engaged, and all this you've been enduring is the result. Next step is going to be to modify the top clip to be positively locked against lifting, or making a replacement worm-bearing hold down that screws or pins in position so the worm has to stay in mesh. This might be as simple as a long threaded rod through the chassis with an ear epoxied to the front of the cover and nuts to hold tension. But I want to verify there is no binding in the geartrain, either when the chassis is pushed or when the upper gear is hand-driven, before we start there.
The gears are not damaged and there is no binding in the geartrain.
With the chassis on the track and the worm gear off, the loco does move when I push the top of the gear wihout stiffness or binding.
Then we are ready to try locking the clip down.
Note the direction, and mechanical advantage, of the worm pressure on the teeth. This lifts the worm as much as impels the teeth. That's the action we have to constrain, and you can appreciate the strength required by how much force you exert with your fingertip to hold the worm in mesh under power.
I do not know if there is enough material left at the broken clip hold-down to increase it with JB weld enough to make an 'eye', then use the eye as a guide to drill the gearbox side and put in a short pin as a positive hold. There may be other approaches to the same action, like filing a hook in the leg.
It seems to me that making a positive hold-down for the front of that clip is the more definitive fix, as it would act right over the worm bearing and not far to the side out of axis. This might be as simple as an L-bracket epoxied to the front of the gear tower and a piece of plate epoxied to the top of the clip, both match-drilled for a bolt and nut tensioned and then held with a drop of removable Loctite or Glyptal. Or perhaps a spring clip.
Ideally one of the actual model-railroad mavens here will have a more elegant solution, or have repaired this type of drive.
Overmod Then we are ready to try locking the clip down. Note the direction, and mechanical advantage, of the worm pressure on the teeth. This lifts the worm as much as impels the teeth. That's the action we have to constrain, and you can appreciate the strength required by how much force you exert with your fingertip to hold the worm in mesh under power. I do not know if there is enough material left at the broken clip hold-down to increase it with JB weld enough to make an 'eye', then use the eye as a guide to drill the gearbox side and put in a short pin as a positive hold. There may be other approaches to the same action, like filing a hook in the leg. It seems to me that making a positive hold-down for the front of that clip is the more definitive fix, as it would act right over the worm bearing and not far to the side out of axis. This might be as simple as an L-bracket epoxied to the front of the gear tower and a piece of plate epoxied to the top of the clip, both match-drilled for a bolt and nut tensioned and then held with a drop of removable Loctite or Glyptal. Or perhaps a spring clip. Ideally one of the actual model-railroad mavens here will have a more elegant solution, or have repaired this type of drive.
I am convinced that it is just a poor design and the worm gear has a lot of stress when it rotates and trys to move the gear which then moves the other two gears which then rotate the #177 wheel with gear axle, attached by rods to the other wheels!
That is a lot of force needed , with plastic gears and it just looks to me that strength is not there.
Anyway, the cover will not stay on and maybe a new rod solution might be the answer.
If that is what you suggest, pictures of this method will certainly help!
It's not so much a 'lot' of force as that it is levered at an angle, and the crappy clip does little in its damaged state to accommodate it. All you need is something that positively holds down the bearing at the end of the worm that is rising up; that could be as simple mechanically as a spacing block or shim on a U-shaped bracket pinned to the sides of the tower.
I have forgotten whether it is the clip or the side of the tower that is defective in the piece you have. A logical approach if it is the former might be to try to reconstruct the clip with a little epoxy and careful filing, but I think you have done that.
I wonder if there is room to file a groove across the clip on the deflicted end, pass thin strong thread or fine insulated wire down both sides, and tie it off at the bottom with the cover temporarily clamped fully down. That ought at least to get it running for testing.