Rebuilding a Series Starter Motor

Before you begin on your quest of rebuilding your starter motor, the first thing you should do is check all your grounds, and leads. These should be clean and well connected. A good way to have your grounds wired is a large cable from the battery’s negative post to the frame, and another large cable from the frame to a starter mounting bolt. The positive lead goes from the battery to the starter button, then from the starter button to the positive terminal on the end of the starter motor.
So now that you’re sure the starter motor is getting sufficient power and it is necessary for you to rebuild the starter, we can begin. Series Land Rovers have very simple electrics, and so is the starter motor. It’s actually very easy to repair your own starter if you understand the principles behind DC motors. In the picture below you can see the major components of your starter motor. The armature, coils, rotor, brushes, and inside the yoke is the field coil.
Electricity comes from your battery, and runs through the brushes, into the rotor, it then runs through the coils, creating a magnetic field, then back out the brushes and back to negative side of your battery. It’s the creation of this magnetic field that makes everything happen. The magnetic field generated in the armature is attracted to and repulsed from the field coil. This makes the armature rotate. As the armature rotates, the brushes send power to different coils, and it spins more, and hopefully starting your engine. As you can gather, there is very little to wear out on these old motors. So when your starter begins to die, many times it’s either a bad ground, or the brushes/rotor that’s the culprit.
To begin, remove the starter from your Landie. First disconnect the battery, undo the positive cable to the rear of the motor. There are two bolts that hold it to the engine. Once you get it on the bench, remove the cover band around the case. The next step is what separates us from the animals; you’re going to make a tool. A metal clothes-hanger from the closet will work. Cut it to a length so that you can hold it comfortably, and bend it in two places so that it has a U shaped hook at the end. This is our brush removal tool. The brushes are held into place by a spring. You hook the spring and pull it back so that you can remove the brushes.

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