The 2001 Mercury Grand Marquis came standard with a 220-horsepower, 4.6-liter V-8 engine. This full-sized sedan also came standard with recirculating-ball power steering. This steering system consisted of six main components: a steering gear, pitman arm, center link, drag link, tie rod ends and an idler arm. The pitman arm transferred the movement of the steering gear to the steering linkage. The idler arm sat on the opposite side of the Mercury's steering linkage and mirrored the movement of the pitman arm. Replacing the idler arm on the 2001 Grand Marquis requires the use of a special tool, known as a pitman arm puller.
Start the Grand Marquis and position the wheels so they are straight. Shut the vehicle off.
Raise the front end of the Grand Marquis, using a floor jack, and slide jack stands under the Mercury's frame rails. Lower the vehicle onto the jack stands and remove the floor jack.
Crawl beneath the vehicle until you reach the steering linkage. Locate the idler arm -- the arm connecting between the center link and the Grand Marquis' frame.
Remove the cotter pin from the idler arm stud going through the center link, using needle-nose pliers. Remove the idler arm-to-center link nut and washer, using a ratchet and socket.
Position a pitman arm puller so the center screw touches the idler arm stud and the claws grip the center link. Tighten the pitman arm puller with a ratchet and socket until the idler arm pops free from the center link. Remove the pitman arm puller.
Remove the two nuts securing the idler arm to the Mercury's frame, using a ratchet and socket. Remove the idler arm from the Grand Marquis.
Set the new idler arm on the mounting studs on the Grand Marquis' frame and hand-tighten the nuts. Guide the idler arm stud through the hole in the center link. Install the new washer and nut -- included with the idler arm -- on the idler arm stud and hand-tighten the nut.
Tighten the idler arm-to-frame nuts to 85 to 97 foot-pounds and the idler arm-to-center link nut to 43 to 47 foot-pounds, using a torque wrench and socket.
Insert a new cotter pin -- included with the idler arm -- through a notch in the nut and through the idler arm stud. If needed, slightly tighten the nut, using a ratchet and socket, to line up the notches in the nut with the hole in the stud. Bend the cotter pin legs in opposite directions, using needle-nose pliers, to lock it in place.
Grease the ends of the idler arm, if applicable, by pressing the end of a grease gun on the 1/4-inch brass fittings on either end of the idler arm and pumping the gun until grease oozes out of the idler arm. If you idler arm has no grease fittings, then it is a "permanently" greased system and no grease is needed.
Raise the Mercury off of the jack stands, using a floor jack, and remove the jack stands. Lower the Grand Marquis to the ground.
