How to repair Takara Tomy S-21 Yufuin No Mori?

Hi all,

Looking for a bit of advice here...

My son received an imported from Hong Kong Takara Tomy S-21 Yufuin No Mori as a birthday present from his grandmother. Initially the train ran fine, but since has been very sluggish if it runs at all.

So, being the good, fairly mechanically savvy dad, I open things up to assess the situation.

This particular train uses a drive unit I have never seen before. It has a two-speed (geared) drive unit, and I can't figure out how to open it, without completely destroying the outer casing.

I know the problem is electrical, and it's NOT the switch.

The way the drive unit behaves, it seems like there's a problem with the motor brushes, or a bad connection inside the drive unit itself, as it seems to be orientation-sensitive. When the drive unit has the switch in the on position (either I or II, doesn't matter), the motor does not run. However, if you give it a push, sometimes it'll go. The weird part, is that it runs more strongly upside down, then right side up.

The top of the drive unit appears to be sealed by a plastic clip (same color and material as the drive unit), but the clip is glued to the drive unit, effectively sealing the top half together.

There is a single screw on the left side, near the bottom. Removing that screw, the lower half of the drive unit will separate slightly. But with the top half sealed, there's no way to get all the way inside to further diagnose the issue.

Does anyone have any advice for me?

all i can say is good luck! they sure dont make it easy

[Super]

Hello Grumpy_Tyrant haven't seen you in a while, glad to see you back.

The glue that holds that plate is not permanent and the plate should be easily popped off. You don't need to replace the plate after your repairs. I don't currently have an extra 2 speed motor in my repair parts box to show you pictures. For all the youngsters out there do not attempt this without the help of a parent or adult. What I use is a thinner pocketknife blade to get under that plate and try to pop it up. Move around the plate until it comes off. Sometimes there will be a stubborn part and the plate will break but as long as it is no longer covering the seam down the middle of the housing you will be alright. Once you get that top plate off you can open the housing by opening the top and front clip. Be careful here because there is a spring and you don't want to spill out the gears until you know their orientation inside the housing. Taking a closeup picture of the inside will help you put them back into the right place when reassembling. While I have a motor open I like to lubricate the gears and their shafts using a little lithium white grease for gears generally used trains and remote controlled cars. That Yufuin No Mori is a fine train, let us know how it goes.

[Ucwepn]

I have had a shinkansen drive unit spill it's gears onto the table, that shinkansen never ran again be careful when opening the drive unit

Thanks to everyone for their replies. Glad to know that the glued-on top plate isn't necessary for operation after the repairs have been completed. I will keep this in mind and pry off the top plate at the seam, as gently as possible.

I'll let you all know how it goes...

[Super]

Good luck!