1993 Buick Century Owner's Manual - Page 215

5. Remove any rust or dirt from the wheel bolts, mounting surfaces or spare wheel. 6. Place the spare on the wheel mounting surface. IA I CAUTION: Rust ordirt on the wheel, or on the parts to which it is fastened, can makethe wheel nuts become loose after a time. The wheel could come off and causean accident. When you change a wheel, remove any or dirt from rust the places where wheel attachesto the the vehicle. In an emergency, you can use cloth a or a paper towel do this; but be sureto use to a scraperor wire brush later, if you need to, to get all the rust or dirt off. '.: .a.