Over time the wheel block gears on the G-Scale Kalamazoo Toy Train Steam Locomotives fail.  The issue is that there is a plastic gear attached to the drive shaft for the wheels.  Over time the plastic gear wears out. Kalamazoo Toy Trains went out of business a long time ago and only used locomotives are available.  My only option I thought was to purchase another locomotive and use the plastic gears as replacement.  Eventually I wanted to work on how to 3D print the gear and attach it to the drive shaft.  After more searching I found Harftield Engines used the same design on their locomotives and  they sold spare parts.  I called the parts department and was informed that they company had closed down but they still had some parts available to sell.  Luckily the shaft with the gear was available and I bought several of them.  

Attached are some pictures of the process.

Turning the engive over, remove the floating 2 axles in the front.  Remove the screws holding the drivers for the wheels.  This then releases the engine block and it can be pried out.

Remove the screws from the sides of the engine block, remove the screws from the wheels and the engine block will come apart exposing the grears and motors.  Be careful and not lose the springs and lead conductor that is used for the track voltage pickup on each of the wheels.  Replace the wheel shaft which is the problem and you will be back up and running.

Changing this motor block from DC to DCC is a challenge as you can see there are not individual wires for the track pickup and the motor.  I will leave that for another blog later on.