Help!!! My Makita 9227c is making a weird noise internally!

[vdog0531]

I have had my makita rotary for about 8 years now. I am a weekend warrior on my cars and friends cars. Not used in a shop or for pro use. I used the hand lock on the back of the buffer head to switch out backing plates, like i`ve done hundreds of times, and then i went to start buffing again and when i pull the trigger and it gets to about 1000 rmps (give or take) there is a violent rattle noise that can be heard and almost felt. As the speed increases, the noise gets worse. As the buffer started to slow down, the noise will slow as well. I took the head off (the piece where the backing plate screws on) and found no debris or anything. I tapped the trigger with that piece off and there is no noise. It sounds as if the manual lock button could be hitting the ring gear piece but i don`t see any signs where it`s hitting. I spin the head piece by hand and don`t hear anything abnormal, but i`m also not spinning it nearly as fast as the buffer spins it. So... has anyone ran into this before? Any ideas on what it could be? Any help would be great, thanks!



Vernon

[Ron Ketcham]

Did you get into the "drive gears" at the head of the buffer, where all the grease lubricant is?

Then look at the bearings where the armature ends fit into bearings.

Both may be dry and from what you have posted, may require some new bushings/bearings and some good hi-temp grease.

[vdog0531]

yes, i have i stripped down. the drive gear and the ring gear have no visible damage or excessive wear. they are both nice and tight. It sounds like the little lock out button that you push in when switching backing plates is not releasing all the way and making contact with that ring gear... but again, A, i dont see where it shows that it`s making contact and B it moves freely up and down and doesn`t appear to be staying too far in. So i dont know what the hell is going on with it.