Public Transport Station Tram Modification Version 2

Here is a better way to motorize the tram from LEGO Set #8404 Public Transport Station.

This mod doesn't require you to change the shape of the tram, or extend anything; however, if you are using Battery Box #8881 (The one with the holes to fit in LEGO Technic snaps), then removal of the roof, or extending the top will be necessary.

You can see the shape of the tram is the same; except for the right side of the tram. The battery box is too tall, so I used parts of the roof to dress the top as best as I can. If you use Battery Boxes 8878 or 88000 (Basically the ones that fit in LEGO bricks.), then the roof can be kept on. I don't have those battery boxes; therefore, I cannot keep the roof.

Here you can see the modification I made using the Technic beams, axles, gears, and a universal joint. The rubber wheels give the tram traction when going along the track. I added rubber bands on the wheels to make them thicker

Here are the ball joints and the universal joints between the two cars. Behind the 24 tooth gear is a small LEGO motor. The motion from the motor is transferred through the gears, through the universal joint, and through the last couple of gears, which turn the wheels. 

The LEGO Technic battery box is too tall to fit inside. I used parts of the original roof to keep the same style. 

Overall, this mod isn't difficult. To take it a step further, you can integrate the Power Functions IR Receiver (8884), the IR Speed Remote Control (8879), and the Light Set (8870). I'll make another post on motorizing the tram with remote controls if I can get my hands on them. Out of all the modifications of motorizing the tram I've seen on YouTube, they all required the pre-made train motor (8866 or 88002), which required them to extend the tram to accommodate the motor.

Here is a couple videos of the tram going up a 12.8 degree slope:

This video is sideways. Please turn turn your head clockwise 90 degrees for the best viewing angle.