# Arnold N scale S2 engine



## N5CJONNY (Nov 5, 2015)

I recently obtained this Arnold n scale S2 with Seaboard road name. The engine seems to run good and looks great. The one bad thing is that I did not do my home work and learn about the potential problems of this engine before I bought it. It seems that due to a design flaw there is a potential that over time problems with the gears meshing properly could be an issue and as a result there could be gear tooth damage. This will cause noise and performance issues. Does anyone have this engine and could someone add to this information and possible solutions. I love the engine and hope to keep it for a long time. Any input about this is greatly appreciated. Thanks.

http://www.modeltrainforum.com/attachment.php?attachmentid=111505&stc=1&d=1449149990


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## Viperjim1 (Mar 19, 2015)

I to have the Arnold cow and calf , both powered, and in removing the shell mine has the motor in the middle and a spring running in each direction that is stretched out over the gear that drives the others gears. This to me seems to be the Achilles heel of that design . I don't know if you have had the shell off , hopefully yours is not like mine, and it's a switcher , short consist moving , not full train consists will be its demise.


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## rrjim1 (Mar 12, 2015)

I own two Arnold S2s, mine ran great never had a gear problem. When I changed completely to DCC I parked them, because there a major pain to convert to DCC .


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## spookshow (Jun 5, 2015)

The gears pressed onto the axles (and the idler gears in the truck gearcase) have a dimple on them, resulting in a thin spot. As a consequence, the gears pressed onto the axles may crack at the dimple. You'll know if this is the case because an S-2 with cracked drive gears will make a clicking noise as it rides the rails. You can usually identify the axle with the bad gear by holding the locomotive in your hand and gently applying force to the wheels. The wheels should not move, but if one does, it probably has a cracked gear (which is now slipping).

Northwest Short Line (nwsl.com) sells geared replacement wheelsets for the S-2. Part numbers are 2679-6 and 2680-6 (two different flange sizes).

Cheers,
-Mark


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## N5CJONNY (Nov 5, 2015)

Guys thanks so much for the helpful tips on this engine. I try and keep the load on this engine to a minimum, so as not to cause the gear problem.

Spookshow- I will check that site out. Thank you for that information.


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## pmcgurin (Sep 7, 2010)

I have the Canadian Pacific S2, and I have run it for at least ten years without trouble. I was using it at slow speed, though. I have run Kato and Atlas locos at sustained high speeds, continuous running, and burned those out eventually. Anything can be worn out.


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