N Scale Bachmann GP40 Chassis Replacement

B-T Nov 19, 2023

  1. B-T

    B-T TrainBoard Member

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    So...my Bachmann GP40 (Boston and Maine) in down for extreme maintenance due to it barely moving at full throttle, and I was wondering, is/was there any KATO or Atlas chassis that would be somewhat compatible with the shell, just because, I really dislike B-Mann's diesel chassis. If anybody can help, but can only find used, I am totally fine with that (my best running/cheapest locomotive is used, while this nearly brand new GP40 bearly moves)
     
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  2. digimar52

    digimar52 TrainBoard Member

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    When you are referring to the engine as "brand new", does that mean it's from the 2018/2019 release of Bachmann GP40s as described by Spookshow here: http://www.spookshow.net/loco/bachgp40.html ? If so, I wouldn't ditch the chassis. Spookshow describes it as even to if not better than the Atlas one.

    The older chassis, especially the first one are really crappy (I can confirm that. I have owned one of the second bunch). But if it's the new chassis it is worth to invest some time in error analysis.
    Obvious things to check are for instance:
    - Is the voltage reaching the pcb? The truck wipers might have lost contact.
    - Are there bindings in the mechanism?
    - Does the motor run freely when taken out of the chassis?
    - Is there some sticky goo in the mechanism? Early Bachmann diesels were massively overlubed. No ides if this still happens.
     
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  3. B-T

    B-T TrainBoard Member

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    My chassis looks very similar to the newest one (DC, but I think it is DCC ready and it as a spot in the fuel tank for a speaker). I have cleaned the heck out of the wheels, got quite a bit of stuff off (this would be about a month ago), ran a little better, but not super noticeable. I also checked for binding, but there didn't seem to be anything noticeable (other than what had been there since the beginning). I have tested running the motor outside the chassis the only way that I know of (connecting the trucks/worms to the motor, just like inside of the chassis), but then it wouldn't run. I also have checked to make sure it wasn't over lubed, but if anything, it would be under lubricated or about what it should be by my standards (not super great, with only three locos - this guy, an old atlas RS-11 (haven't really taken it apart), and a Bachmann 0-6-0 and this one).
     
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  4. mtntrainman

    mtntrainman TrainBoard Supporter

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    One thing I have found is... don't tighten the 2 frame screws to tight. Just lightly 'seat' them and then back em off about 1/8 of a turn. I have had the same problem with some Atlas models doing the same thing. JMO
     
  5. B-T

    B-T TrainBoard Member

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    I will try that once I decide whether to get a new motor (I am very positive I got a bad motor due to it not running at all) or I try to find a new chassis for it. Speaking of that I am trying to figure out what bachmann's warranty means. Here is what I found according to their website (https://www.bachmanntrains.com/home-usa/):

    "Warranty Information

    Effective 1-1-2022. Prices subject to change.

    This warranty is valid for ORIGINAL PRODUCT OWNERS ONLY in the US and CANADA. This warranty does not apply to any other persons or locations.

    Bachmann's Lifetime Limited Warranty covers motorized motive power units only. Under the warranty, Bachmann can decide whether to repair or replace an item at their discretion.Items less than a year old are fully covered and will be serviced or replaced at no charge when accompanied with registration card and proof of purchase.

    Items less than a year old are fully covered and will be serviced or replaced at no charge when accompanied with proof of purchase (sales receipt). User modification to units voids the product warranty. Note: even if in original packaging, units purchased at flea markets, railroad swap meets, garage sales, online auctions of previously owned products, and similar venues are NOT covered by this or any other warranty.

    $39.00 -
    • All HO and N Scale standard non-DCC locos

    $49.00 -
    • All HO and N Scale Non-Sound DCC locomotives
    $65.00 -
    • All HO and N Scale Spectrum®, E-Z App® and Sound Locomotives
    $79.00 -
    • Williams and On30
    $115.00 -
    • Large scale

    All accessories, power packs and speed controllers, and Plasticville USA® items are covered for 90 days only. Contacting Service

    Please pack your item to protect from rough handling during shipping. When possible, please use the original packaging to return you item for repair. Please include a note with your return address, daytime telephone number, e-mail address, and a description of the issue with your product.
    Also before returning your product(s), you must remove any customer-installed DCC decoders. Failure to remove a customer-installed decoder will automatically void the warranty.

    Repair inquiries, or general inquiries may also be sent to:

    Bachmann Customer Service
    1400 East Erie Avenue
    Philadelphia, PA 19124


    Bachmann's Service Department is available Monday through Friday from 8:30 am to 4:00 pm (All Times Eastern). Customer Service for all scales can be reached at 215-533-1600 or Fax at 215-554-6734."

    Does that mean that I have to pay 40 bucks to ship it or is that to fix it? I have also modified the shell by making it a high-hood as well as repainting it, I don't know whether that means that the warranty is not valid anymore (I got the locomotive in August), but then I only modified the shell - not the chassis?
     
  6. ggnlars

    ggnlars TrainBoard Member

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    Not sure I understand how you checked the motor. In the CB motor the two frame sides provide the electrical connection to the two sides of the motor from the track. If you pull the motor out, then you have to provide a connection to each of the motor connections. I do this by using alligator clip wires from the power supply.
    motors will burn out if the spend much time in stall at high power(voltage).

    A healthy motor will produce sufficient Torque to run the engine by itself at or greater than 100 SMPH.

    The engine weight and motor torque will produce sufficient draw bar force to pull more than 50 cars.

    The environment that these models are run create significant internal torque that often shows as a reduced pulling capability and a slower top end speed.

    cleaning the Angeles site important, but it does not impact the internal Torque requirements. In this case the wheels are part of the electrical circuit. The dirt causes a voltage drop to the motor. This will impact the speed, but it is not the largest factor unless the wheels are to really dirty.

    The bigger contributors here are grit in the bearings. This grit can be dirt from the layout or just old grease that has turned to goo. Thus goo tends petrify as it ages. This can happen from the point of B manufacture to when you put on your track. L A little lube goes a long way here. Manufactures tend to over do it.

    one of the first things I do is clean out this original grease. For these models I sparingly use a bearing oil. While gears usually require grease, these plastic models do well with a light amount of oil.

    I use a small pointed artists brush to apply the oil. You want to lightly hit all bearing surfaces. That is a rotating shaft running in a round support. These include the wheel axles, the gear support shafts & the motor bearings, you have to be particularly careful with the bearing near the motor brushes. You do not want any oil on brush contact with the commutator.

    Finally the problem may be a cracked gear. This problem is common on older Bachmann locos(really it extends to others who used a similar design). A cracked gear will eventually jam the gear system stalling the motor. These need to be replaced as soon as possible.

    what you need to do will become clearer after you have done tha above.
    Good luck.
     
    Last edited: Nov 22, 2023
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  7. B-T

    B-T TrainBoard Member

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    Recently (last time I ran it - about a month ago), I tested it and it probably was going at about 50-75 SMPH. When I last ran it, I only had about 10 railcars (40-70') and at full power, it was barely moving with 8 cars, let alone 50. I have not tried cleaning out the original grease, so I will have to try that when I get a new motor/truck (one truck broke - still works without anything different other than it coming off when I remove it off the track the truck pops off - didn't affect the performance at all. At this point, I think my motor needs replacement, unless I can find a good chassis to replace it (unlikely). Wonder if there is anywhere else to get Bachmann motors with much cheaper (or free) shipping, because I don't know if I want to pay more for the shipping than the actual product (~10 bucks for shipping):rolleyes:.
     
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  8. JBrown

    JBrown TrainBoard Member

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    What does the motor look like? I have some Bachmann motors out of there FM units...
     
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  9. B-T

    B-T TrainBoard Member

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    Here is a photo of the motor from the Bachmann parts store:

    [​IMG]
    My motor is slightly different due to the wires breaking - thus making it unusable (that is my assumption anyway)
     
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  10. JBrown

    JBrown TrainBoard Member

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    I don't think 10 dollars shipping is much to get your engine running....
     
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  11. ggnlars

    ggnlars TrainBoard Member

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    That is a coreless motor. Sure enough they list as a replacement on their web site. I am surprised & pleased that they are using those.
    I suspect the problem is the truck coming off. it should not do that. Likely the truck attachment tabs have broken off. That needs to be fixed.
    There is a spline between the motor coupling & the truck coupling. This transmits motor power to the truck. If the spline is not there or not properly connected to the truck & motor, then that truck will act as a brake. The wheels will not turn because the worm gear is not rotating. This condition will impact the speed the unit can achieve.
    It also will lead to several other bad things.
    I think the first order of business is to find out how the truck should be installed so it will not come off. If the assembly is damaged the broken parts need to be replaced.
    I do not think your motor is bad at this point.
    The paper work that came with the engine should show a schematic of the drive showing the appropriate parts. That is where you should start to trouble shoot the truck issue.
     
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  12. B-T

    B-T TrainBoard Member

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    I am planning on getting a new motor + a truck shortly. Once I start thinking about it, it isn't that much, other than the fact that it is my most expensive locomotive!
     
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  13. B-T

    B-T TrainBoard Member

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    I somewhat suspected that the broken link is causing a minor problem, but it is still running fine (the truck). Also one of the rubber rings around the motor broke as well as the wire connecting the motor to the lights (the lights, I very much dislike, due to the fact I am using it on a heritage RR that never operates in the dark. To my understanding, the motor requires the lights to run, and presently I am trying to think of how to get rid of the lights, but not getting rid of them at the same time if anybody knows what I mean.
     
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  14. ggnlars

    ggnlars TrainBoard Member

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    Who told you the motor needs the LED to run? The motor is a DC motor. It responds to voltage level across the red & black wires. They might be doing some electronic tricks to step the voltage down on the high end to reduce the top end speed of the motor, but it will still run without those. You need to understand the circuits they are implementing. Particularly if this model comes in DC & DCC models. Simplistically, all you need to do is directly connect track power appropriately to the red & black wires. Red needs to be connected to the right side of the frame aft looking forward.

    What kind of event caused this damage?
    The motor is inclosed between the two frame sides. The wires from the motor attach to the proper locations on the mother board. This is bolted to the top of the two metal frames. The two sides are also bolted together. It is an unusual event that would cause the motor damage you’ve described.
     
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  15. B-T

    B-T TrainBoard Member

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    I am mainly guessing that it needs the LED to run, but once the wires broke at the edge of the motor (I think they slipped inside quickly afterwards, perhaps causing a short (or at least that is my assumption - granted I am newish to the hobby (started in late June/early July). The wires broke sometime during transportation in the parts bag, I don't know when exactly, probably due to rough handling.
     
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