Now, be careful. To buff the sheave faces clean. You want to use burgundy Scotchbrite material. Its finer than the green Scotchbrite and thus easier on the magnesium sheaves.
You don't want to use brake cleaner or carb cleaner or even water to clean out the clutches and CVT housing.
Just use the Scotchbrite and then wipe clean with a clean, damp, towel.
The chattering is indeed a function of damage to the belt. Remove the belt and inspect it for cuts, glazed portions, or roughened sections. All of which will make noise, and vibration.
My advice. If someone you're with is in that deep, use a machine with a winch. If someone is in that deep...and you try to pull them out...you need to have one of the straps that stretches.
Back up as close as you can to the stuck vehicle. Securely connect the snatch strap to each machine. Then you take off and go as hard as you can until the strap stretches and stops you.
Plant the brakes. The the stuck vehicle start turning the wheels slowly, use a little steering and the machine will eventually get out. You may have to repeat this several times. But beats the **** out of smoking a belt!!!
Hunterworks sells several brands of belts and Todd can help you select the correct one for your machine.
Just talking experiences!!
Pirate