This document describes a patent for improvements in friction couplings used in baling machines and other power driven machines. Specifically, it details a friction coupling that provides an audible alarm when slipping occurs. The coupling has two plates between which are fabric-lined slip discs. When slipping causes the slip discs to rotate, it actuates an audible alarm such as a bell. Alternatively, ratchet teeth on the slip disc can click against a spring to produce an audible warning of slipping. The invention provides a way to detect and warn of slipping in a friction coupling.