Q: How to replace the pinion seal on Mercury Cougar?
A: To remove the rear axle cover, raise your vehicle and support using a jack stand. Remove the bolts and nuts holding the rear axle cover to the axle mount. Put in place the bolt for the rear mount into the lower bolt hole allowing pivot forward of the axle. Slide the driveshaft forward and let it rest on the driveshaft hoop. Take off the nuts that keep the carrier on the front mount. Slowly lowering the carrier will give access to the companion flange. Use a pinion nut removal tool or a wrench and socket to get rid of it. Get rid of the companion flange as well. A screwdriver blade should be wedged between the housing and seal, the metal flange lifted using a locking plier then seal pulled out with locking pliers. To install, use an installer drive or pipe slightly smaller than a seal. Look for burrs on mating surfaces, remove them if any with emery cloth, and put back reference marked companion flange over pinion shafts.
Q: How to replace the Differential Seal on Mercury Cougar?
A: Remove half shaft assembly. Use seal puller or prybar to remove seal. Connect slide hammer to puller and remove seal. Lubricate seal and align with housing bore. Use driver or socket, extension, and hammer to install seal. Ensure seal is not cocked, if so, install new one. Install half shaft assembly.