Noisy old Athearn SD40 with Mashima Motor

[Sunshine Express]

I have just bought this well kept older Athearn SD 40 Diesel which has been fitted with a Mashima Can Motor.It came from a reliable source,and I am not unhappy with the  purchase as the price was right.I have never owned a Mashima Motor unit before.
Experience tells me most old Athearns are  a bit noisy,and I have no argument with that.
Without the body it is still very noisy. Are there any suggestions to reduce this above normal   noise ?. Thanks for  any suggestions. Owen

[Doneldon]

Owen-

Let me begin by suggesting that you note that this board is mainly for Bachmann products, and that it is paid for by Bachmann. Consequently, I encourage you to return often, but not with questions about products from manufacturers which do not support this board.

As for your question, there are some things you can do. The first is to make certain that your drive system is aligned, supported where necessary and lubricated as well as possible.

Then, consider your shell. It serves two purposes: First, it is the decorative and informative part which allows modelers to identify the type of locomotive and the railroad which ran/runs it. Second, It encloses the mechanical parts, both hiding them from view and muffling their noise. Thus, you will hear more noise (ordinarily) when a locomotive's shell is removed than when it is on. If that's not the case, it's because the shell itself is a source of noise. That may be because it is loose and vibrating. The fix is to ensure that the shell is tightly and correctly installed.

But ... there may still be more noise, and this is what I'm guessing is your problem: the shell is being induced by the mechanical sounds to vibrate and, in effect, amplify the undesirable mechanical noise and vibration. In my experience, large diesels, with their comparatively large, flat sides, are the most likely offenders. The solution is to dampen that vibration. The easiest way I've found is to smear a small amount of some flexible, heavy-bodied substance on the inside surfaces of the body shell, with special attention to the sides. With some models the top can be a problem, too, but the molded details on the roof are in greater relief and therefore have more mass than the sides, so they are much less likely to be induced to vibrate in harmony with the drive train. Be sure that the material you use is plastic safe, that it will cure to a non-sticky state, and that you have left sufficient clearance between the dampening material and the works. I have found that plastic-safe latex or silicone caulk works very well. Materials which cure hard, like most glues, don't work very well.

Please feel more than welcome to return here to share your modeling experiences and if you questions about your Bachmann items.
                                                                                                                                                                                                    -- D

[Sunshine Express]

I apologise for the error in listing,and have been a long time member.Thanks for your courteous message  Owen Robinson

[jbrock27]

That said, there are certainly many times here that products other than Bachmann's are readily discussed.  There is no need for you to apologize for your post Mr. Robinson.

Question: how is the Mashima secured to the frame?
Do you have any idea what is generating the noise?  The stock motors on these models are known to be quiet and the Mashima has an even better reputation.  Oftentimes the Athearn flywheels can be the source of noise, but since this has the Mashima instead, that is unlikely.
If you cannot determine the source of the noise while intact, my suggestion is to take the drive line and trucks apart.  Clean all plastic parts in water and dish liquid using a toothbrush.  Look for plastic "flash" that may need trimmed.
Is this the kind of Athearn that has bronze bearings at the wheelsets?  
Clean all metal parts, including wheels with a solvent and a rag.  Assuming you don't find any parts during disassembly that need replacing, reassemble using small amount of Teflon grease for gears and worms and appropriate oil in small amounts on the metal drive rod that connects to the worms where they meet their bronze bearings, front and back side of the worm.
If you describe the noise better, I might have a better idea of what is making it.  If I had to guess on the info currently available, I would guess something is out of alignment.  It sounds from what you describe, the noise is there before the shell in is place.
Do you have a wheel gauge?
Please let me know if you have any questions.

[Woody Elmore]

Back in the day Athearn units had a reputation for being noisey - due to the plastic gears. One trick was to buy Dr. Scholl's moleskin and use it to line the inside of the shell.

[jbrock27]

No doubt, the plastic driveline usually being the culprit.  The OP stated it is noisy w/o the shell.

[Brewman]

I have the same problem with an old blue box GP38-2. I took the trucks apart and looked at the gears. I didn't see flash or burrs but they were dry. I have greased all the gears and oiled bearings. We will see how it is Saturday at the club run day. Google "Athearn tune-up" for ideas and suggestions.

[jbrock27]

I have read that site myself, many times over and probably every other posting on the subject as well.  I too, have not found flash in the gear teeth, even though I have read so much about that.  I have found "black particles" after soaking the plastic parts (including gears) in the soapy water.  Not sure what they are or where they came from.  I think the flywheels and the driveline are main noise culprits, bc if you assemble a truck after cleaning and greasing the gears and roll it on the track, the only noise it makes is the sound of the wheels rolling on the track.
I am not down with the "toothpaste" trick since I don't get noise from the gears, plus I am not convinced you need to "break in" or "wear" the gears-they seem to mesh just fine.

[Len]

I've found most of the noise in 'Blue Box' Athearn's and early Proto units comes from slop in the drive train universal joints. There's enough space for the ball & pin ends of the shaft to rattle around in the sockets they plug into.

A small dab of silicon caulk, which stays flexible enough for the joint to still bend, will often quite the noise down considerably. The other thing to check is those white motor mounts. They get stiff and brittle with age, and may need to be replaced.

Len

[jbrock27]

Thanks Len for the tip on the silicone.  With regard to the motor mounts, I agree with you.  I do one of 2 things; the "best" but more costly, is to buy the new black motor mounts that are screwed in to replace the dried out white ones.  The other option, is to take the white ones out (assuming they don't crumble apart) clean them up with dish liquid and warm water and then glue them back in place with E6000 adhesive, with the motor placed in them.  I also clean the frame from grease, oil, etc, before hand.  I apply the adhesive to the frame and the underside of the mounts, including the "nubs".  Not too much is needed.  If you do this, you have to make sure you do what you want to do with the bottom motor clip first (like isolating for DCC or soldering a wire to it for directional lighting), bc while the motor can still be removed, it often is not possible to do it w/o destroying the mounts at that point.

[Len]

Don't pack the socket with silicon, just a small dab to keep the shaft from moving around is all it takes.

The new motor mounts & screws are cheaper in bulk. $3.98 for a pack of 24 #84027 screws, and $8.98 for a 12 pack of the #84026 mounting pads. The #84028 set of 4 pads & 8 screws is $4.98. Or a 12 pack of the original white plug in mounts is $7.98.

Len

[richg]

I apologise for the error in listing,and have been a long time member.Thanks for your courteous message  Owen Robinson

if in doubt with other brands, a very good set of forums is at Trans.com. Kalmbach also sells the Model Railroader and other train magazines.

Use those forums for HO scale in other brands.
I have posted the Bachmann forums link there since some did not know Bachmann had its own forums.
The Bachmann forums would be overwhelmed by other modelers if not kept in control.

We have to remember, model railroad is a huge family. I remember many years of all I had were two different brands of MRR magazines. Many times I had to go to a building called a library to look up MRR info.

Rich

[jbrock27]

Thank you again Len.  
Do you think the adhesive I mentioned, which stays somewhat flexible and does not harden like 2 part epoxy, will work to do the same thing as the silicone?

Do me a favor?  And shoot me a PM about where you have found the mounts.  Thanks much.


lexon, ahh, I mean RichG, I go to other train boards all the time; they are rich with information.