The 4WD system on certain vehicles fails when cracks in the actuator's diaphragm create vacuum leaks. The diaphragm on this Dorman OE FIX actuator uses a mesh-reinforced rubber material to provide three times the durability of the original design. This part is compatible with the following vehicles. Before purchasing, enter your vehicle trim in the garage tool to confirm fitment. [Chevrolet Blazer: 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005] - [Chevrolet S10 Blazer: 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994] - [Chevrolet S10: 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004] - [GMC Jimmy: 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005] - [GMC S15 Jimmy: 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991] - [GMC S15: 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990] - [GMC Sonoma: 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004] - [Pontiac 6000: 1988, 1989, 1990]