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HO SD40 Locomotive, Kansas City Southern #631

Item No.
Athearn - ATH87227
Pre-Order | Pre-Order
Brand Logo
4.8 out of 5 Customer Rating

HO SD40 Locomotive, Kansas City Southern #631

Item No.
Athearn - ATH87227
Product $169.99
Add Ons
Estimated Total: $169.99

HO SD40 Locomotive, Kansas City Southern #631

Item No.
Athearn - ATH87227
4.8 out of 5 Customer Rating
Product $169.99
Add Ons
Estimated Total: $169.99
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Product Details


  • 81” Nose w/ rear porch mounted brake wheel
  • Chessie/KCS style rock plows
  • Larger Dynamic Brake housing
  • High-mounted truck brake cylinders

During the 1970’s and 1980’s, KCS adapted a simplistic, yet very noticeable scheme on their freight diesels. Ordered from EMD in 1971, these later phase SD40’s were the backbone of the fleet next to their SD40-2 brethren.


  • Bi-directional LED lighting
  • Coupler Cut Levers
  • Rubber MU hoses
  • Exhaust stack
  • Curved radiator fan grab iron
  • Fine scale handrails
  • Photo-etched stainless steel windshield wipers
  • Separately applied wire grab irons
  • See-through dynamic brake, radiator fans and cab windows
  • Frame mounted bell (unless noted)
  • Detailed 4,000 gallon fuel tank (unless different capacity is noted)
  • Flexicoil-C trucks with high or low brake cylinders (per prototype)
  • Separately applied air tanks
  • McHenry® scale knuckle couplers - Kadee® compatible
  • All-wheel drive with precision gears for smooth & quiet operation
  • All-wheel electrical pickup provides reliable current flow
  • DCC-ready features Quick Plug™ plug-and-play technology
  • Improved 5-pole skew wound can motor with flywheels and multi-link drivetrain for trouble-free operation
  • Non-sound version features 21-pin NEM DCC plug
  • Wheels with RP25 contours operate on all popular brands of track
  • Highly-detailed, injection molded body
  • Painted and printed for realistic decoration
  • Fully assembled and ready-to-run
  • Window packaging for easy viewing
  • Interior plastic blister safely holds the model for convenient storage
  • Minimum radius: 18” — Recommended radius: 22”

    • Newly designed can motor is more powerful and quieter than before
    • DCC & sound models feature Tsunami2 sound with dual cube speakers
    • LED lighting for long life and reliable operation


    • Onboard Tsunami2 DCC/Sound decoder
    • Dual cube speakers for optimal sound quality
    • Sound units operate in both DC and DCC
    • Engine, horn, and bell sounds work in DC
    • Some functions are limited in DC
    • All functions NMRA compatible in DCC mode
    • Operating lighting functions with F5 and/or F6 (Flashing ditch lights, beacon, etc.)
    • Excellent low-speed operation
    • Program a multiple unit (MU) lash up with lead unit only horn, bell, and lights
    • Many functions can be altered via Configuration Value (CV) changes
    • CV chart included in the box


    In 1966, EMD updated its locomotive catalog with entirely new models, all powered by the new 645 diesel engine. The SD40 had 3,000 hp from a turbocharged V16. 856 examples of this locomotive model were built for American railroads, 330 were built for Canadian railroads, and 72 were built for Mexican railroads.

Product Specifications

Reporting Mark KCS
Scale HO
Lighted LED
Sound Ready
Axles 6
DCC Ready/21-Pin NEM
Era 1941-1970, 1971-1990
Prototype Manufacturer EMD