Skip to main content

Greetings y'all it has been awhile.

I wanted to ask a question to those that have Sunset Model Locomotives. How do you lucubrate  your motor? I recently acquired a Sunset Models Southern Pacific Lines P-8 (4-6-2) from 2006 or 2007. I want to say factory new, but I could have been re-wrapped pretty good. I noticed when I did a bench test at home her motor was a bit loud and noisy compared to other locos I have. And when I was doing a test run at the club layout it seemed like she was binding a little bit at slower speed, kinda Jackrabbit-ish.

Attached is a photo of four screws I removed from the body trying to get inside to lube/grease the motor and video of how loud it is.

Any input to safely remove the shell would be appreciated.


Greg R.


Images (1)
  • screws removed: Circled in red. 2 sets each
Videos (1)
loud motor
Original Post

Replies sorted oldest to newest

@Lou1985 posted:

Doe sit have EOB? If so the EOB motor driver is 99% your issue. I've got a SP MT-5 4-8-2 from a year prior and it ran all sorts of jerky at low speed and the motor had a horrible whine sound. I ripped out all the EOB stuff and replaced it with an ERR Cruise Commander and RS 5.5. Smooth as silk now.

I do not know. It is a 2006 run.

These engines are factory equipped with Pittmans, ….some 3rd Rail engines have ginormous honking flywheels, ….sometimes 2 of them!… sure to inspect older equipment for bearing failures, I’ve seen one waller out the nose bearing. You’ll have to pull it apart to examine that. Grab the nose drive on the motor and see if it has movement on the vertical plane, most will have some shaft end play (horizontal plane) You need to eliminate mechanical woes before installing or replacing X-pensive electronics….


Very nice loco!  I agree with Lou1985 about the EOB control system, I'm not a big fan of it.  Depending on how the "momentum" is set up, that could be what's responsible for your jackrabbit starts.  It's possible that the tach reader and flywheel are misaligned.  If the flywheel is loose on its shaft or wobbling around, that could also cause jerky starts.

Honestly, it doesn't sound like a lack of lubrication.  If you're hearing a high-frequency whine (not audible to me on the video), it's probably the EOB.

I'm not 100% sure what year 3rd Rail introduced their "quiet drive" (and generally, it is quiet.)  If your loco has the Quiet Drive, you'll see that it consists of a belt-and-pulley arrangement connecting the motor with a layshaft set well down in the chassis.  If the belt tension isn't correct, or if the pulleys aren't rotating in the same plane, the belt flaps around.  Remember, a brass body shell is resonant and amplifies all of these sounds-- there's a reason they don't make tubas out of die-cast metal

When you open it up, please post another video of it running and we'll go from there.  Also, if you can disconnect the motor leads coming from the control board and run the motor on pure DC, that will eliminate any electrical noise from EOB, and further aid in troubleshooting.  Good luck!

Last edited by Ted S
@UPMav#488 posted:

Ok, How many more screws do I need to remove and from where to get the Locomotive Shell off? I removed 2 from the front and 2 from the rear by the cab. I do not want to pull to hard in trying to get the shell off.

There's usually a single screw under the smokebox (which is accessed by removing the pilot truck) and two under the cab that will free the boiler shell.

The two screws at the rear of the cab (that you already removed) and one long screw up through the frame at the front and into the boiler weight are what hold the boiler/cab on.  You have already exposed the head of that screw.  In the center of your red circle on the right is the slotted screw head, with a hole in the center of it.  A thin blade screwdriver is used to remove it.

The two smaller screws that you removed from each side of the big screw are what hold the cylinder saddle to the frame.  You should re-install these screws before removing the boiler, otherwise more will come apart than you want.

Add Reply


OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)

Link copied to your clipboard.