“The pinion gear is attached to the amateur
shaft, it drives the spindle gear. Over time, the gears will wear from normal
use. They could wear much faster if the tool was
overloaded. Wear will cause excessive gear lash and noise. Eventually the gear might fail causing the
spindle to stop spinning and unload. Replacing the pinion gear is a repair that
you can do yourself and I’m going to show you how. Hi, I’m Mark Sodja. Do-It-Yourself repairs like these are easier
than you might think. From lawn machines to cordless drills, kitchen
mixers, outdoor grills, our how-to video walk you through each repair from start to finish. Doing it yourself means never having to do
it alone. Let’s get started. I’ll begin by removing the rear handle cover. I’ll also remove both of the motor brush covers. Next I’ll remove the motor brushes. I’ll pull the brush spring back and lock it
out of the way with a little plastic post. I’ll remove the brush wire and then I can
remove the brush from the holder. Next I’ll remove the separator fan. The fan is screwed onto the amateur shaft. It has a reverse screw. I’ll hold the motor from spinning with the
lockout button you’d use when you change grinding wheels, then I can remove the fan. Now I’ll separate the gearbox and amateur
from the rest of the motor. I’ll pull the amateur away from the gearbox. With the amateur removed, now I can remove
the pinion gear. It’s held in place with a nut. Now I’ll install the new pinion gear, I’ll
slide it onto the shaft and secure it with a nut. I’ll apply a little grease to the pinion gear
and then reinstall the amateur assembly to the gearbox. As I install it, I need to make sure that
these tabs on the metal plate align with the slots on the gearbox housing. I’ll tap it with a rubber mallet just to make
sure I have the bearing set. Now slide the amateur back into the motor
housing and secure the gearbox to the motor with the screws. Now I’ll reinstall the separator fan. Again, this is reversed thread. I’ll lock out the amateur with the gearbox
lockout button and tighten the fan up. Now I’ll reconnect the lower half of the handle
to the motor housing. As I do this, I’ll make sure that the wires
are tucked out of the way. Now I’ll reinstall the brushes. I’ll throw the brush wire through the arm,
install the brush into the holder, lower the arm down against so the brush can’t touch
the commutator and reinstall the brush wire, and then I’ll place the tension spring back
over the arm and I repeat this for the second brush. Now I’ll reinstall the handle cover and secure
it with the screws and the brush covers. That’s how it takes to install a new pinion
gear in your power tool. Be sure to check back often for new videos
and expert advice. If you found this video helpful, give us thumbs
back and leave a comment.”