Q: How to replace universal joints in a driveshaft on Mercury Grand Marquis?
A: A press or large vise will be required for this procedure. It may be advisable to take the driveshaft to a local dealer service department, service station or machine shop where the universal joints can be replaced for you, normally at a reasonable charge. Remove the driveshaft as outlined previously. Using a small pair of pliers, remove the snap-rings from the spider. A pair of needle-nose pliers can be used to remove the universal joint snap-rings. Supporting the driveshaft, place it in position on a workbench equipped with a vise. Place a piece of pipe or a large socket with the same inside diameter over one of the bearing caps. Position a socket which is of slightly smaller diameter than the cap on the opposite bearing cap. To press the universal joint out of the driveshaft yoke, set it up in a vise with the small socket pushing the joint and bearing cap into the large socket. Use the vise or press to force the cap out, stopping just before it comes completely out of the yoke. Use the vise or large pliers to work the cap the rest of the way out. Transfer the sockets to the other side and press the opposite bearing cap out in the same manner. Pack the new universal joint bearings with grease. Ordinarily, specific instructions for lubrication will be included with the universal joint servicing kit and should be followed carefully. Position the spider in the yoke and partially install one bearing cap in the yoke. Start the spider into the bearing cap and then partially install the other cap. Align the spider and press the bearing caps into position, being careful not to damage the dust seals. Install the snap-rings. If difficulty is encountered in seating the snap-rings, strike the driveshaft yoke sharply with a hammer. This will spring the yoke ears slightly and allow the snap-rings to seat in the groove. If the snap-ring will not seat in the groove, strike the yoke with a brass hammer - this will relieve the tension that has set up in the yoke, and slightly spring the yoke ears. This should also be done if the joint feels tight when assembled. Install the grease fitting and fill the joint with grease. Be careful not to overfill the joint, as this could blow out the grease seals. Install the driveshaft, tightening the companion flange bolts to the torque specifications.