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I'm an O scale guy, but one of the members of my club had me look at his American Models SD-60 locos. These are true scale locos, NS short hoods.

AAAAAnd they click like mad when going around the club layout. We popped off the shell to look at the drive line. Yep, it has a nylon type motor shaft coupler in the middle, and two black plastic output shaft couplers on either end of the driveshaft (U joints?). Each coupler has a groove that engages a T fitting on the driveshaft... at they have split inside, but only on one side of each coupler. The other end looks like an interference fit onto the output shafts.

These locos have to be 10 years old... can you still get parts? Where? Maybe someone has figured our plastic isn't the way to go?

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Volphin posted:

I'm an O scale guy, but one of the members of my club had me look at his American Models SD-60 locos. These are true scale locos, NS short hoods.

AAAAAnd they click like mad when going around the club layout. We popped off the shell to look at the drive line. Yep, it has a nylon type motor shaft coupler in the middle, and two black plastic output shaft couplers on either end of the driveshaft (U joints?). Each coupler has a groove that engages a T fitting on the driveshaft... at they have split inside, but only on one side of each coupler. The other end looks like an interference fit onto the output shafts.

These locos have to be 10 years old... can you still get parts? Where? Maybe someone has figured our plastic isn't the way to go?

Volphin,

I'm not clear on your terminology, but from what I gather, the small cup on either the motor or truck has split?  In any case, American Models stocks just about any part for their locomotives.  Go to their website americanmodels.com to order parts.  You're looking for "U-joint set" on the diesel parts page.  If you're feeling like only replacing the broken part, give them a call and tell them what you need.  Ron, the owner, or anyone else who answers the phone, will be glad to help you out. 

Are you sure it's the driveline's  u-joint cup that's making the noise? I have an older RS-3 that was doing the same thing, and it turned out that a couple of the nylon gears in the power truck had a tooth missing.  Replacing them was a snap, especially at a buck a gear (we S guys tend to be a cheap bunch).  Once the truck's side frame is off, you can see if any gears have missing teeth.

As you know, diagnosing a problem remotely is difficult, but if there's any way we can be of further help, feel free to post on this forum.  By the way, I live close to American Models' place here in Michigan, so your living in Tennessee makes it necessary to order parts via mail. 

Thanks for the reply Jerry!  My terminology may be off for sure!  I'm not really an S scale guy... You are correct... the little cups are cracked.  I just didn't know what to call them!  HAHA.  I have not checked the gears yet, but I will.  The units are off site right now, but will do more investigation Tuesday at our club meeting.  What leads me to believe it was the U joint cups is the obvious damage and the fact it only makes the noise in one direction... hence I thought the U joints were holding on the uncracked side, but were slipping or something on the cracked side.  At a buck a pop for those gears, we should probably just add that to his order.  Even if they are fine, it never hurts to have spares in the tool box.

Where in MI is American Models?

Rusty,

Yes, and here's how close I live to it...

Volphin,

No need to apologize, model trains are model trains, no matter the scale, I got your drift.  Just replace the cups and see if the noise disappears.  And if you don't need the gears, don't bother.  It's very rare any of them ever crack.  I have a number of AM offerings, and the RS-3 is the only one I've had gear problems with.  Probably a bad batch of gears.  Then again, I've had it on my layout for years, and I've probably not lubricated it enough.  In any case, hold off on ordering any gears until you have inspected them.  By the way, there are three idler gears per truck and are easily inspected by rotating the flywheel by hand.  Besides the three idler gears, there's one on each axle too.  You'll see them when you take off the truck side frames.

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I replaced the universals that came in my old original AM FP7 with Hobbytown of Boston universals, and it is now the smoothest runner of all my AM diesels. Don’t let the HO designation fool you, these u-joints are probably more robust than most of the ones seen on most O-scale locomotives, and far better than anything in S scale! Give Nick an order at:

<http://hobbytownofboston.com>

Bill in FtL

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