F locomotive just hums, won't run

[skippygp123]

My grandson has an older F locomotive.  Don't know the make but it carries the Great Northern RR logo.  Anyway, it won't run.  Just sits on the track and hums.  The headlight works, so I know it is getting some power.  I have tried turning the wheels by hand, but they won't budge.  (Are they supposed to turn easily?  I truly don't know.) 

Have tried other engines and they run fine so I don't think it has anything to do with the track. 

Can anyone shed some light on what might be wrong with this engine and how I could fix it?  (I'll need exact instructions....I'm not very familiar with electrical terms/motors or what things look like but if you explain exactly what I need to do, I can probably do it.) 

Thanks

[selector]

This may be better addressed over in DCC and Electronics, but I have read that you can have several problems.  Corrosion, dried lubes that are like brick, and even glazed rotating parts in an older open-frame motor (they would need gentle sanding or something to get their surfaces clear).

Someone should pipe up who can actually help, but in the meantime, if you wish, it might be better to post this over in the other forum.

 

[garya]

It may need cleaning and/or lubing, but I need a little more info:

• What scale is it? N, HO, 3-rail Lionel (O-27)?
• Is there a make or manufacturer on it anywhere? If you turn it over, do you see a name or country anywhere on the body?
• Any idea how old it is?  Has it been stored for a while?

 

[skippygp123]

It is HO scale.  I couldn't find anything on it to indicate a manufacturer, sorry. 

It hasn't been used in awhile but is clean (not dusty and dirty on the outside).

[hobo9941]

We need to know the scale, if it is Lionel, etc. If it is Lionel, it is an AC motor. Are you trying to run it on a DC transformer? Or is it a DC motor, and are you trying to run it on an old Lionel AC transformer? Need more info. If it is old, it is not likely DCC. Are you trying to run it on a DCC system? Too many questions here, need to be answered.

[skippygp123]

HO scale.  Doubt if it is DCC...  Other locomotives run on the track.  Headlight works but wheels won't turn, even if I turn the engine over and try to turn them with my fingers (are they supposed to???)  Using DC power to the track. 

[Darth Santa Fe]

The only HO F-unit I know of without the manufacturer's name on it is Athearn's F7. You can tell if it's an Athearn or not by four holes on the bottom with rubber clips in them. If it has them, it's an Athearn.

If you take the shell off, can you turn the shafts by hand? If not, something in the gearing is jammed, and you'll have to open the gear box to fix it (Athearn parts are easy to disassemble). If you can turn the shafts easily, then the motor's not getting enough power to run. I had that problem once, and found that the motor brush springs (located under the gold clips on the top and bottom of the motor) weren't putting any tension on the black carbon brushes. Stretching them a little fixed the problem.

[Darth Santa Fe]

wheels won't turn, even if I turn the engine over and try to turn them with my fingers (are they supposed to???)

On all but the very cheapest drives, no, they shouldn't turn by hand. Most HO scale steam and diesel uses a worm drive, which is a screw-shaped gear over a regular gear.

EDIT: Here's a link to a diagram of an Athearn F7: http://hoseeker.net/assemblyexplosionAthearn/Assembly%20Explosion%20Athearn%20F7A%201973.jpg

[skippygp123]

Thank you, so much, for all your help!  I have printed off several copies of the diagram. 

What is the best thing to use to clean the gears and other parts?  What should I use as grease for them when I put them back together?  How much grease should I use (how much is too much??)? 

Can I test the motor after I have removed it from the base?  If so, how do I do that? 

 

[Darth Santa Fe]

The best way to clean gears is with soap, water, and a toothbrush, although I usually just use the brush alone (after getting the main stuff off with tissue paper).

A quality plastic compatible grease (from someone like Labelle) is the best to use, but Vaseline works too. I add a little at a time and turn the gears to work it in until the gears don't have any dry spots.

The motor can be tested separately by touching a wire to the top brush plate and to the bottom brush plate.

[cacole]

If it's an older Athearn locomotive, it probably has the metal strip across the top of the motor that is supposed to be transferring power from the wheels at each end, and this metal bar easily corrodes and loses pickup for the motor.  The best cure for this problem, other than replacing the metal strip with wire, is to remove it, burnish both ends with fine sandpaper or emery cloth, and rebend it so it makes good contact at both ends.

 

[AltoonaRailroader]

The only HO F-unit I know of without the manufacturer's name on it is Athearn's F7. You can tell if it's an Athearn or not by four holes on the bottom with rubber clips in them. If it has them, it's an Athearn.

If you take the shell off, can you turn the shafts by hand? If not, something in the gearing is jammed, and you'll have to open the gear box to fix it (Athearn parts are easy to disassemble). If you can turn the shafts easily, then the motor's not getting enough power to run. I had that problem once, and found that the motor brush springs (located under the gold clips on the top and bottom of the motor) weren't putting any tension on the black carbon brushes. Stretching them a little fixed the problem.

Hold on Darth, if it's an REALLY old Athearn it will have an open frame motor that held down with two screws I believe. The one I have is like that and the generation before that had rubber band drives, where as the one I'm talking about has little brass drive shafts.  Just had to chime in, no offense.  

[StillGrande]

I would be willing to bet it is an old Bachmann and it has lost a gear inside.  I remember having an old F unit with the exact same problem.  If you open it up you will find the motor running but there is a plastic gear which has either broken or fallen off.  If you are lucky it is just pushed out of place and you can snap it back on.  Otherwise, it is not going anywhere.  The gearing in the trucks will keep the wheels from turning easily by hand, if at all. 

[R. T. POTEET]

Listen closely! If you can hear a "ding" then you know that this locomotive is a Humdinger from the 1950s.

[wm3798]

Can you post a photo with the shell on and one with it off?  That will go a long way to identifying the body...

It could be something as simple as a piece of ballast wedged into one of the drive gears in the trucks.

Lee 

[garya]

Can you post a photo with the shell on and one with it off?  That will go a long way to identifying the body...

It could be something as simple as a piece of ballast wedged into one of the drive gears in the trucks.

Lee 

Most HO F unit shells are easy to take off.  Spread the shell near the fuel tank; most F units (Athearn, Bachmann) have tabs that lock in to the shell.  You may have to remove the front coupler to get the shell off.

[Don Gibson]

SOUNDS LIKE an old 3 rail Lionel with the directional relay not throwing, but you haven't specified make, or scale, only the "GN "paint job.

If it's 2 RAIL HO, you have a more serious problem - power is getting to the motor, but not turning. (gears binding? motor brushes? hardened lubricant?). No, gears won't turn by hand. New motors ar are $40. Rubber bands break. Good luck,

Professional repair may be in order. Question: at today's $25hr. labor rates , is it worth it? Used Athearn F's go for $5 -$10 .

[wjstix]

A picture, even just of the outside, would be helpful in deciding who made it. I don't know if Athearn made a GN F-unit until recently, so it might be something else. Depends on how old is "older" - a 1950's Globe, a 1970's Mantua/Tyco (which did make a Big Sky Blue GN F unit, I had one), a 1990's early Stewart engine...??

If you can get the body shell off, if it's an open-frame motor, try turning the motor with your finger. It could be something got lodged in there and is stopping the motor from spinning.

[skippygp123]

It is not Lionel or any 3-rail engine....it is HO

[emdgp92]

If it's one of those infamous Tycos, it could be a gear problem. Sometimes, one of the plastic gears would slide off its shaft, or the metal one (attached directly to the motor) would slide over just enough that they wouldn't mesh. Annoying, but a drop of super glue should be enough to take care of it.

[wjstix]

Is the engine dark green and orange, or is it dark gray / white / sky blue?? If it's the latter (GN's "Big Sky Blue") paint scheme, it's almost certainly an old Tyco. I had one of those c. 1972, until recent years I don't think anyone else made a RTR F unit in GN BSB.

[skippygp123]

Finally got the time to look at the engine closely.  It is an Athearn...has the 4 plastic plugs on the bottom. 

I took the shell off and tried to turn the motor by hand but it wouldn't go.  I pushed the motor out and it rotates when I turn it by hand.  However, the wheels still won't turn. 

I tried turning the "slotted coupling" (that's what the part is called according to the assembly diagram I downloaded) but it won't turn at all on either set of wheels. 

I took the gear box clip off the bottom of one set of wheels and see oil residue but can't see any foreign matter by the gears. 

I can't figure out how to get the "worm housing" off to see if there is a problem inside that.  Can someone help me by giving step by step instructions?

Thanks!

[jeffrey-wimberly]

The worm housing just pops off. See where the screwdriver is pointing? put the end of the screwdriver under the edge of the cover and pry up on it using the loco frame as a fulcrum while holding the thumb of your other hand lightly on the cover. They like to fly. Carefully remove the worm gear. You don't want to lose the square bearing on the end of the shaft.

You already have the bottom clip off so I'll skip that. There's another clip on top. The screwdriver in the next photo is pointing to it. You remove it the same way as the bottom clip. After the clip is off you should be able to easily pry the truck halves apart.

The third photo shows what you'll find inside the truck. 

 

[Arjay1969]

Here's a good tutorial on how to give the locomotive a thorough tune-up...

http://www.mcor-nmra.org/Publications/Articles/Athearn_TuneUp.html

 

And it does cover the trucks too, so you should be able to trace down the problem.

 

Good luck! 

[richg1998]

Go to this site and try to find a document with a loco like the one in question.

http://www.hoseeker.net/athearnmicellaneous.html

Rich 

[skippygp123]

I'd like to thank everyone for helping me with my grandson's locomotive.  I took it all apart, using your wonderful directions, and found all kinds of green gunk on the worm gear.  I cleaned all the parts and greased them and put the engine back together.  It runs like it was brand new!  Again, thank you!  I appreciate your help more than you can know.