RS-3 disassembly

This locomotive is one of the earliest designs by Aristo. When working on it, you will find that it has a lot of parts.

Special notes on dissasembling re: components of the shell:

To get into it the first time, you need to remove both hoods and the cab as a unit. The top part of the body is actually in 3 parts. These parts are held together inside by brackets. You can, optionally, disconnect these brackets so later you can only remove one part, but often this results in a gap between the cab and the hood, it's your choice. You can always reinstall the brackets later.


My procedure:

There are either 17 or 21 screws you need to remove. If you have no weight in your fuel tank, you can sometimes squeeze the tank sides in to clear the two screws that are right at the sides of the fuel tank, but why bother? I remove the 4 tank screws to get to them more easily, total 21.

  • remove the 4 screws and the fuel tank
  • now start at the ends of the loco, you will find 2 screws at each end, that's 4 more (keep counting, we are at 8)
  • there are 2 more pairs of screws along the long hood (4 total), notice that sometimes the pair nearer the center are sometimes longer and with pointy ends. (12 total now)
  • Now between the cab and the short hood, there are 6 screws, 3 on each side, they hold the battery boxes and the cab and the end of the short hood (that's 18 so far)
  • Now on the other side of the cab, there are 3 screws all in kind of a row - one in the center (almost under the truck) (that's 21 total)
  • Once you have all the screws out, turn the loco right side up, and pull all four handrails out of the cab. Now VERY carefully, lift the shell assembly off by grabbing each hood in one hand near the cab. This will keep you from ripping the brackets out that hold the cab to the hoods.
  • The battery boxes should slip free, if not, tap them lightle to convince them to stay with the chassis. Usually the handrail stanchions will drop out of the battery boxes.
  • Depending on the generation you have, unplug the 2 connectors from the chassis to the wires in the shell
  • Be careful not to pull or twist the hood and cab assembly, you can rip out the screws on the brackets that hold everything together.


Removing trucks:

The simplest way is to pull the 2 screws from the underneath that hold the motor block to the "U"-shaped bracket.. then you can see the 2 wires/plugs to pull out.

When removing the sideframes, notice there are 3 screws that hold them to the motor block. The 2 on top are longer and easy to deal with. The bottom one is often not noticed, it is tucked under the end of the leaf spring and part of the truck frame. It's head is too large and is often stripped, or hard to remove or hard to put back in. I would suggest finding a screw with a smaller head. This seems to be an afterthought by Aristo, since they are re-using their sideframes from the original motor block design where the axles rode in the sideframes and they were really sprung.


If you have ever used the smoke unit, just pop it out before you turn the loco over, keeps from spilling fluid. Just pull on the stack.

These locos have a reputation for impossible to remove screws, resulting in stripped philips holes and the heads broken off. Be sure to use a screwdriver that fits the screw heads well. If you think you will have trouble, heat your screwdriver and place it in the screw slot to help.

I use a bit of armorall (Turtlewax F21) on the screw threads when reinstalling, helps them from seizing up later, and helps screw threads in the plastic from stripping. Notice, as whenever you lubricate a screw thread, less torque is necessary for a firm fit.

Some people have removed the brackets so that the 3 pieces can be removed separately, but I found some gaps between the cab and hoods were apparent, so I left them on. I figure that the brackets were put there by experience from Aristo, and why would they go to the extra expense?

The springs in the sideframes rust easily, if you leave this loco outdoors, or have a humid climate, I suggest you give them a squirt of an armorall type protectant (I use the Turtlewax F21 stuff in the lime green bottle) every 6 months or so...


Notes on another gen 4/5 install:

RJ has an RS-3 with the socket, but it had a meltdown:

Headlight and numberboard wiring

Problem is that there are only 3 wires to each small board in each "nose" of the loco. This means the led headlights share a common ground with the incandescent number boards (and the cab light).

The headlight (F) has red(lamp +6v), blue      long nose


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