Fix Your Busted Diff Plugs A busted diff plug on your Polaris ACE can sneak up on you. Once you strip the threads on your drain plug; you can have a serious leak. That leads to serious diff problems if you don�t fix it quick. Replace your plugs with SuperATV�s Front Differential Fill and Drain Plug Kit. It comes with O-ring seals and a magnet in the drain plug to catch debris. You�ll have the smooth; leak-free front diff you need.