A very good place to start.Check to see if anything has became loose.?
While you're in there snugging things up, follow this suggestion as well.I would pull it apart and check the springs and washers. Also would be a good time to grease it , being 4 years. If it just started sounds like something has changed.
I know that MGW makes a gasket that comes with their shifter and also can be used with other shifters, but in my experience it is completely unnecessary. A thin bead of Permatex works well, and is reccomended per the Steeda Tri-Ax install guide.If it doesn't have a gasket you might want to put one in there also. Probably the two bolts just came loose.