Hi. I’m Mark from eReplacementParts.com.
In this video I am going to show you how to replace the upper spindle bearing on a Makita
grinder. The upper spindle bearing is one of two bearings on your Grinder’s spindle.
Like any bearing, eventually it will wear out. Signs that a bearing is going bad will
be squeaking or squealing sounds coming from the tool; excessive heat in the gearbox area; or sometimes, the shaft will actually come loose and you will be able to move it side-to-side. Replacing the bearing is easy to do. And I’m going to do is show you how.
Upper spindle bearings, as well as many other parts, can be found on our website. Let’s get started. I’ll begin by removing the side-handle and
the guard. The gearbox housing is held in place with four screws. I’ll go ahead and remove those. Now I can remove the spindle assembly by removing the four screws that secure it to the housing. Now I’ll remove the upper spindle bearing. To do that, I use a bearing separator. I place the separator
around the bearing and then I tighten up the nuts on the separator. Just finger tight is
fine. Now I’ll place the bearing separator, with the spindle assembly attached, over my vice. I have opened the jaws so the spindle assembly will just fit between them. Now I can use a punch and a hammer to remove the bearing. Now I can install the upper shaft
bearing. I’ll place it onto the end of the spindle, and, using a socket that has a diameter the same as the inner-race diameter on the bearing… …I’ll place the socket on the race
and tap it in place with the hammer. Now I’ll install the spindle assembly back onto the gearbox housing. And I’ll secure it with the screws. There is an O-ring on the spindle
assembly, so I want to seat the screws evenly as that O-ring slides into place. So I am
just going to work my way around the housing tightening each screw a little at a time. I’ll reinstall the gear housing assembly to the motor assembly… …and secure it with the four screws. Then I’ll finish up by installing the guard… …and the side-handle. And that’s how you replace the upper spindle
bearing on a Makita grinder. If you found this video helpful be sure to give us a thumbs-up
and leave a comment.