Quieting down Athearn Diesels

Discussion in 'HO Scale Model Trains' started by ssw_820, Dec 5, 2003.

  1. ssw_820

    ssw_820 New Member

    My son and I model primarily Southern Pacific. We have a 'boat loads of 'Balck Widow' era locomotives (everyone ever made by Proto 2000, a couple Stewart F Units, and Kato Units). We also model 'newer SP' stuff (Scarlett and Gray). Sp was fairly famous for it's 'Tunnel Motors' (SD40/45-2T's). Athearn makes the only ones in HO scale (to my knowledge. Unfortunately, they all run very noisey (as compared to msot of are other locmotives). You can hear their drive train gearing 15+ feet away! I'm in the process of converting two SD60 Proto 2000 frames (with motors, trucks, weights and circuit boards) to SD40-2T's (using Athearn shells) in order to get quieter SD40-2T's. But I will still have several more Athearns left and really cannot afford the time or money to do all of them this way. I, therefor, need to find a wayu to make them run quieter. I've tried the following:

    1. Replaced the Athearn wheel sets with Northwest Shortline Nickle Silver sets.

    2. Replaced the Athearn Can motors with A-line can motors and weighted cradle mounts, flywheels and drive shafts.

    3. I've bought all new truck assemblies (Athearn)

    4. Followed all the Athearn tuning tips in various publications (removing 'flash' from the gear sets, etc).

    5. Polishing the gear sets with "Pearl Drops" tooth paste and then thoroughly cleaning the gear sets.

    6. Adding gear grease (white) to the gear sets (so far has given the best results, but they run a little warmer now; not too much warmer; definately nohwere near the F units mention by the one member).

    7. I've gone through several sets of drive trucks (front and rear) for each engine. I do not continue with the same trucks after I've tried various 'tricks' that failed. Even the brand new trucks run rough. You can feel it when you 'hand roll' them on the track before they are installed in the locomotive(s).

    I was hoping, after reading the exceptional help given to the guy with the 'hot running Athearn F-unit motor), that someone might be able to give me some ideas or advice to help these Athearn 'Tunnel Motors'. If some other company made them, I would slowly (as money permitted) replace them, but you really cannot beat Athearns's $35 price tag for these (that is how much I find them for brand new on a regular basis). Can't run Southern Pacific in teh 'Bloody Nose era' without these. When detailed, they really look great.

    We have decoders installed in all of them, as we now run all of our stuff on DCC. They are just as noisy now as they were before the decoder installs (decoders will not fix or cause gear problems).

    I have narrowed it down to 'gear slap' in the trucks. if I run the locomoitves with only one truck 'drive shafted' to the motor, they run quieter (doesn't matter which truck). As soon as the other truck is 'drive shaft connected', the noise starts. It's like the trucks are "fighting each other", even though they are both connected to the same motor.

    We ultimately would like to put sound decoders in them as we slowly convert some of our stuff to sound, so this gear train noise is something that will need to be solved. We've also been 'spoiled'by the smoothness and quietness of the Proto 2000, Kato and Stewart Diesels we have as well as the many steam engines.

    Any ideas?


  2. Russ Bellinis

    Russ Bellinis Active Member

    Can you adjust the height of the motor mounting in the frame. The closer you can get the drive shafts to flat or parrallel to the track, the quieter the units will run. I'm not familier with the A-line mount. Does it do away with the white nylon Athearn mount with the pins to go into the frame? If you have those Athearn white mounts, make sure they are tight in the frame. If they ride up just a little, they will allow the motor to "rock" in the frame and cause a lot of noise. If they rock enough, the motor will beat on the inside of the body and sound like the thing is going to come apart.
  3. brakie

    brakie Active Member

    First and foremost your biggest mistake is thinking a Athearn will run as quite as a Kato,Atlas or P2K as many do. Never happen but you can come close.:D

    My friend first you got to realize that the Athearn is a light weight compared to the other brands I named all of those units have the weight needed..Here lays one of the problems a very easy fix.
    Remove the shell and add 4-6 stick on weights(I use A-Line's) this cuts down on the shell chatter..One of the sources of the noise.
    Now follow this steps.
    1.Remove the shell add the stick on weights to the inside top of the shell.
    2.take the unit apart-completely.Clean off all the grease from the gears.
    3.Inspect each gear for burrs and other foreign matter,check the gear box as well.
    4.Reassemble the trucks making sure everything seats properly.
    Now test the trucks by pushing them (or raise your test track) to see how far they roll.They should roll very freely.
    5.Check the drive shafts and make sure they are not bent or old of round.Put aside.
    6.Now turn the motor and flywheel by hand and make sure both turn very smooth and freely.
    7.While you are at it buff the truck booster area on the frame-do not grind the Little knob off that the trucks fit on.This will give you better electrical contact.
    8.Reassemble the unit be sure every thing seats properly including the motor.
    9.Use ONE SMALL DROP of oil on the gears,shafts and bushings.WARNING: DO NOT USE MORE THEN 1 SMALL DROP OF OIL!!
    10.Now work the oil in place by turning the drive by hand using the flywheel..

    This should fix the noise problem.

    Regardless of what you may have been told grease is NOT good for a Athearn drive..I can not explain this and I have tweaked several Athearn locos over the years by using the above steps.All of my Athearn will run very smooth and fairly quiet..

    I have always stated that the Athearn drive is to light and needs more weight.Athearn is now adding the extra weight needed in the newer RTR releases and the Genesis line (except for the steamers)..
  4. Vic

    Vic Active Member

    Another Old Time Train Repair Guy "Chimes" In

    The folks that have replied already have pretty much touched all the bases. The combination of a hard plastic shell and a full metal frame works just like a sounding board for any vibrations.

    Just a few thoughts....

    1. Take a look at the drive train. Disassemble all of the universals and make sure that there is no flash in them that would cause them to run "out of true".

    2. Are the holes in the universals on center...both on the motor shaft and at the gear boxes.

    3. Look at the spline shafts between the unversals. Could be that one or more of them is deformed (slightly bent)

    4. Flywheels....are they true....both round and shaft holes on center.

    5. Don't forget to check out that worm that drives the worm gear on each truck too...make sure its centered on the shaft.

    6. If nothing works I'm wondering if stuffing some foam rubber in the shell would dampen the noise.
  5. Rusty Spike

    Rusty Spike Member

    Wow. I just parked my Athearns. Makes the price we're paying for the Protos and Katos seem less steep when you look at the effort it takes to get them to run like they should.

    I doubt I'll ever purchase another Athearn engine - the new AC4400 has me tempted, but I'm guessing it still doesn't run like the Protos or Katos and the price isn't that much better.

    Has anyone put the new RTR Athearns on track?
  6. brakie

    brakie Active Member

    Rusty,I have ran the new Athearns at the club and in most part they run just as well as the P2Ks..I will put the Genesis up against the Kato or P2K any day as far as smooth running and in some areas details.

    Rusty,That may sound like a lot of work but it doesn't take that long..Infact I can tweak a Athearn drive faster then most can add the details to a Stewart or Kato loco..:D But then I have years of experience on my side.:D
  7. ssw_820

    ssw_820 New Member

    Thanks for all the information. I guess I was misunderstood in a couple of areas. I realize that the Ahtearns (not the expensive; and I emphasize expensive, Genesos) locomotives normally cannot be expected to run as smooth or quiet as the P2K, Kato and such. Noramlly I would not fuss with them. The only problem is that Athearn is the only HO manufacturer (I understand that N-scale will be finally getting one from Kato?) that makes/made the 'Tunnel Motor' locomotives (famous on the SP). As I stated, I am in the process of converting a P2K SD60 into a 'Tunnel Motor', utilizing the Athearn shell. I also believe the shell to be like a drum set (amplifiying the noises), but I found that the gear noise (though not as amplified without the shell installed) was very noticeable. For this reason, I am trying to convert the P2K Sd60 (complete frames with motors, trucks and everything) to work with the SD40-2T Athearn shell. I only have two. I therefor want to try to get the others to run better. The one with the 'white grease' (light gear grease) runs very quiet, as all the gear slap is now gone. I have removed allthe 'flash' from the gears while wearing high powered magnifyhing glasses. The one that I have installed the A-line motor, NWS NS wheels, flywheels and driveshafts did have a a level armature shaft/driveshaft to worm gear assembly line up. The A-Line motors getinstalled with A-Line weighted motor cradles (not the old Athearn rubber deals). In addition, I have added about 4-6 sticks of lead to the chassis/frame and shell. The locomotive has been 'hard wired' for DCC using a Digitrax DH123 decoder. The decoder does take up some space on top of the motor. The trucks all rolled 'freely' before they were installed, but when you rolled them slowly by hand, you could feel the gears. I went through 3 complete sets of trucks while removing all the 'flash'. Problem was as the 'flash' ws removed, the gear slap increased. Seems the P2K and Kato gear sets all mesh closer. I wish someone would make closer meshing gear sets for the Athearns. I'd buy them, just for my tunnel motors, unless some other manufacturer comes out with affordable tunnel motors (I doubt they will).

    I appreciate all the information and will try it all, again. I'm not one to just 'give up'. As forthe two P2K 'Tunnel Motors' I am 'kitbashing, I will use them as soon as they are don. The only problem with them will be the gear ratios. For whatever reason, Proto installed excessively slow speed gearing in the SD60 (earlier versions), so they are very difficult to MU up with any other locomotive (DDC or DC).


  8. ssw_820

    ssw_820 New Member

    Boy I hate the typing errors I left in the previous message. But, I guess that happens. To make matters worse, I missed them when I previewed the message. Clearly a case of 'seeing what I wanted to say', just not typing it.

    Once again, thanks for all the input. I'll keep trying. I need good running 'Tunnel Motors' for our SP stuff.

  9. Russ Bellinis

    Russ Bellinis Active Member

    I think the biggest problem is that the molds for the Athearn gearsets are probably second only to the molds for the f unit body in age. Since every Athearn locomotive runs those gearsets, those molds probably have more "pulls" on them than anything else Athearn makes. The molds probably should be replaced, but everytime Athearn replaces or upgrades anything, buyers yell about the price increases. Unfortunately new tooling is very expensive, and must be amortised in the cost of the model.

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