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.