A riding lawn mower is usually the type of mower that has this sort of problem. You are ready to drive the mower and let the clutch out like you normally do and then it starts to squeal or grind when you do. You could also experience this when you press down the go pedal on the right side of the lawn mower.
Each of these pedals is moving the springs and drive belt and pulleys. As the pulleys engage the drive belt, they start to spin up and control the direction of the belt. So logically when these bearings in the pulleys are starting to spin, if they are going bad they will make the grinding or squealing sounds.
If your mower has some years on it, the pulleys could be bad and the belt as well. Good practice is to change the belts and pulleys. Some riding lawn mowers have 2 drive belts. One connects the engine to the variable speed pulley and the other from the variable speed pulley to the transmission.
If you need assistance with repairing your riding lawn mower, visit our Locations page for a lawn mower repair shop near you.