The differential on a Dodge Ram pickup takes power generated by the engine and channeled through the transmission and directs it to the rear wheels. The differential must be adequately lubricated to prevent the internal moving parts from wearing down. Occasionally the gear oil must be replaced to replenish it's ability to lubricate. Changing the differential oil on a Dodge Ram can easily be accomplished by the vehicle owner, with only a few simple tools and about an hour to work.
Raise the rear of the vehicle using an automotive jack, and support with jack stands placed under the rear axle.
Locate the differential cover on the back side of the rear axle. Place a waste oil collection pan underneath the cover.
Unscrew the fill plug on the cover using a wrench.
Beginning at the bottom of the cover, loosen but do not remove the bolts that secure the differential cover to the axle housing using a socket.
Unscrew the bolts on the bottom of the cover, using a socket. At this point oil might begin to seep from the bottom of the differential cover.
Tap the side of the cover with a rubber mallet if oil does not begin to seep from the bottom of the cover. Allow the differential to drain completely.
Unscrew the remaining bolts that secure the cover to the axle housing using a socket.
Remove the cover from the axle housing.
Clean the differential cover using an automotive solvent. Be sure to remove the gasket sealant off the mating surface using a flat razor blade. Allow the cover to air dry.
Clean the gasket sealant off the mating flange on the axle housing using a flat razor blade and an automotive solvent. Allow the surface to air dry.
Run a bead of RTV (room temperature vulcanizing) silicone sealant on the axle-housing mating surface. Be sure to run the bead inside the bolt holes.
Lift the differential cover into position on the rear axle.
Screw in the bolts that secure the cover to the rear axle housing and tighten using a socket.
Fill the differential with fresh gear oil, using a gear oil pump. Fill the differential to the bottom edge of the filler plug hole in the differential cover.
Screw the filler plug into the differential cover using a wrench.
Lower the vehicle.
