This is a Driven Clutch Sliding Sheave for Yamaha G1, 2 Cycle Golf Cars. Over time one or more of the six small plastic ramp buttons that the sheave and the spring seat slide against mayl break off. If enough of them break the aluminum ramps will start to rub metal on metal. Once this happens the ramps rapidly wear down and the driven clutch can no longer perform. If you find any of the 6 ramp buttons missing, it is time to remove the unit and rebuild it with parts you can find in this section. Don't delay! If the ramps are metal to metal, chances are it has worn beyond rebuilding and you will need to purchase this Sliding Sheave and the Spring Seat too. Sheave comes with 3 new ramp buttons, seals and bushing. Look elsewhere in this same section for the Spring Seat & Ramp Buttons.
NOTE: If you need to replace either the Drive or the Driven Clutch chances are the Drive Belt needs to be replaces as well. Check the old one for cracks and splits.
And if the Drive Belt is bad, check the Starter/Generator Belt as well.