2001 Mercury Mariner 50-60HP Factory Service Manual, Page 479Get this manual
BIGFOOT GEAR HOUSING
9Replace drive shaft if splines are worn or twisted10If bearing surface is damaged, replace drive shaft and corresponding bearingIMPORTANT: Do not tighten vise against drive shaft11If wear sleeve is deeply grooved allowing water to enter gear case, remove (and discard) sleeve using Universal Puller Plate (91-37241) and mallet