fall inside a hole

Tomy Train repairs

Originally written April 3, 2026

Tomy Train was an American and European series of chunky reversing trains with magnetic couplings that used Plarail-style track. The standard trains almost all used the same chassis and even the odd chassis like the lit Hi-Speed Express or some of the Thomas series trains use the same reversing gearbox arrangement in a slightly different chassis.

Rubber traction tires have pretty much all hardened - Tomy still makes and sells the same size of tire as a Plarail spare parts item, and packs of several pairs can be bought online. Dry-rotted tires have far less traction and will sometimes spin freely around the wheel or crumble away, and they are essential to proper operation.

Motors can be seized up with time, and the contact strips can also become tarnished at their points of contact or corroded from leaky batteries, so disassembling the chassis can sometimes be required to get a train going again.

Six screws hold the chassis together from the bottom. The gearbox has a mechanical reversing mechanism triggered by special diagonal protrusions in the reversing tracks like the mechanism previously used on Round-Trip Plarail.

A metal sliding switch is spring-loaded to flip over and locate securely in forwards to reverse gears. The switch slides one of the gears between powering the output rear axle directly or though a reversing idler. White or blue gears were used at different points, and it seems like the motor pinion is usually brass, which is nice. A spring-loaded clutch is included as well... a nice compact reversing gearbox.

The battery compartment, contact strips, and power switch are part of the upper chassis section, with the motor's terminals forming a crush connection with the upper contact strips when the two parts are screwed together. The rotating power switch actually also nudges one of the gears over so the gearbox goes into neutral for free-wheeling - make sure the power switch is in the on position to make reassembly slightly easier. The screw pointing upwards from the underside of the top section hold a blanking cover over a second battery slot - the tooling even has the directional information molded in. It seems that like the older Big Loader chassis that the compartment was designed for two AAs in parallel but I suspect that many people would be used to installing batteries in alternating directions to make series packs and end up short circuiting both cells together in a loop. In parallel, mixed batteries would also try to balance each others charge out, which I don't believe is particularly ideal either. Either way, battery acid should be neutralized using vinegar or lemon juice and cleaned off, and the second compartment can be left open and used if the intended slot is not making good contact or if one or the other contact is broken off.

Old Tomy gears are known to split and spin on their axles with age. Replacing gears will produce better results than gluing for traditional gears which have split through the teeth - the split tooth will not mesh properly with its mating gear. If a gear like the contrate gear has split at the stem but not all the way to the ring of teeth the collar can sometimes be glued back in place successfully as the meshing face is intact.