How do you repair the gasket on the rear dif of a 1999 Ford Crown Victoria police interceptor?

Answer 1

Input Axle seal: Have someone remove the drive shaft and the yoke to access the pinion seal. They then need to remove and replace the old seal then reinstall the yoke and drive shaft. Unless you have access to a lift and impact, I'd suggest paying a professional to do it. If it is not the axle seals, but is simply the large (~12 inch diameter) gasket bolted onto the back of the differential (~12 bolts). You can replace the gasket easily by removing the differential access cover with a pan to catch the oil (2 quarts/liters) and remove the old gasket. You can replace the old gasket with a silicone bead or with an actual gasket. If you choose to buy a gasket, make sure you buy the right one (two ring gear sizes are available, the interceptor version should have the larger one, 8.8 inches I think, but ask your nearest dealership with you vin #). Clean off the gasket surface of the differential housing and the cover plate, reassemble the gasket/cover/bolts (there's a bracket holding the e-brake cable which is held on by the upper bolts) and torque the bolts to speck (the service desk of your local dealership should be able to tell you the proper torque). Remove the fill plug from the drivers/engine side of the differential (you'll need a 1/2" drive wrench which will fit into the center of the plug, and replace the oil with the specified weight of oil. Reinsert the fill plug and wipe surfaces clean to be able to see if oil is leaking out.