Mine started making a lot noise. Kind of a laboring and squeaking. I loosened the screws that go into the center brace rod that goes between the brushes. Noise is gone. Don't know what would cause it to become to tight. I had never touched them before.
The gears are plastic, ZERO need for grease and it won't keep them from wearing. The gears go when you seize the brushes all of the sudden by running over the cord or a spotting rag etc. Normally it's just the one gear that will strip.
Grease is the last thing you want dripping out of a CRB.
yep, impact screwdriver did the job no problem. Screws had corroded a little. I don't use the 20 inch much.
Also agree on the tipping the machine when starting it. It becomes a good habit after awhile.
Yesterday I had a fellow cleaner text me to ask if he could use one of my Brush Pros because his gear stripped. When I bought my first machine I talked to the owner because I was going to buy an extra set of gears just in case. he told me that I only need the small one because that is the one to go first. I just gave the other cleaner my spare gear and he was good to go!