Your vehicle's rear end or differential cover, just like any other automotive or engine cover, is regularly exposed to plenty of heat, moisture, and force. Over time, these damaging elements will take a toll, especially on the rubber gasket that helps the cover prevent leaks. Once the gasket or the actual cover wears out, you'll have to replace the cover. Fortunately, installing a new one isn't a difficult task so long as you're equipped with the right tools and have enough working space at the garage. Here's what you need to do:
- Torque wrench
- Rubber gloves
- Putty knife, scraper, or razor blade
- Penetrating oil or lubricant
- Brake cleaner or degreaser
- Basin or container
- Differential liquid/ oil
Step 1: Prep up your car.
After putting on safety equipment such as gloves, jack up your car and make sure it's securely supported by jack stands. The car should be high enough to give you enough space underneath to work on the rear end cover. Then, depending on your car make, you'll have to drain the differential fluid out. Place the container or basin underneath the differential housing and unbolt the plug to drain the liquid.
Step 2: Remove the differential cover.
The number of bolts you need to remove with a socket depends on your vehicle's make. A car usually has at least 8 rear end cover bolts. If some of the bolts are stuck, spray them with some penetrating liquid to loosen them up. After removing all bolts, you should be able to pull off the cover. If not, gently tap it with a hammer until it falls of.make sure you catch the heavy steel cover. Another technique is to remove the bolts and leave one behind. Then tap the cover until it loosens up and remove the last bolt so the cover won't suddenly fall and injure you.
Step 3: Clean the mating surface of the rear end under the vehicle.
The mating surfaces of the cover and the rear end under your car are covered with a gasket. You have to remove traces of this rubber material before you can attach the new differential cover. Use a razor blade, scraper, or putty knife to get rid of any remaining rubber material or grime from the surface. You can also wipe some brake cleaner or degreaser on the mating surfaces to ensure a clean, solid adhesion.
Step 4: Apply the sealer.
Test fit first the cover by making sure the bolt holes are aligned. Once you've confirmed the fit, put sealant on the mating surface of the new differential cover, around 1/8-inch thick. Attach the new gasket on the sealer-covered surface, making sure that the bolt holes are aligned. Then apply some more sealer on the mating surface of the rear end. Wait for a few minutes to let the sealer set.
Step 5: Attach the new differential cover.
Place the new cover in position. Adjust accordingly until the bolt holes are aligned, but don't move the cover around too much. Fasten it in place by using the new bolts that come with the new cover. Tighten the bolts in a star pattern. Make sure to follow the manufacturer's torque specifications to avoid over-tightening the bolts.
Step 6: Refill the differential liquid.
Once the cover is tightly bolted down, reattach the drain plug into the base of the differential. Then remove the filler plug and refill with differential liquid by using a funnel. Dip a glove-covered finger inside the differential to know if it's full. If your entire finger is wet, stop putting in liquid. Reattach the filler plug and your car should be good to go.