The differential and final drive gears in a rear-drive vehicle are housed in the rear axle housing, or carrier. The axle housing also contains the two drive axle shafts which must be removed prior to replacing or servicing the differential.
There are two types of axle housings found on modern automobiles: the removable carrier and the integral carrier.
To remove and replace the differential, you should first lift the vehicle on an appropriate hoist.
The removable carrier axle housing is open on the front side. Because it resembles a banjo, it is often called a banjo housing.
Typical removable-carrier axle housing. Courtesy of Ford Motor Company.
The backside of the housing is closed to seal out dirt and contaminants and keep in the lubricant. The differential is mounted in a carrier assembly that can be removed as a unit from the axle housing.
To Replace a Removable Carrier:
- Loosen the differential cover bolts and allow lubricant to drain into a suitable container.
- Remove the housing cover.
- Remove the rear axles and propeller shaft.
- Remove the driveshaft and companion flange.
- Scribe reference marks on differential bearing and bearing caps. These are to be used during reassembly.
Mark the side bearing caps before removing them. Courtesy of Ford Motor Company.
- Remove bearing cap bolts.
- After removing the bolts, use the pointed end of a roll head prybar in the bolt holes to pry the caps off. Pry back and forth, first on one side and then then the other.
- Once the caps are loose, you can pry against a solid part of the carrier to remove it from the axle housing.
Removing an integral carrier from the housing.
- Once the differential assembly is out of the housing, the ring and pinion gears can be inspected and replaced if necessary.
- Reverse the removal process to replace the assembly in the housing.
The integral housing is most commonly found on late-model cars and light trucks.
An exploded view of an integral-carrier axle housing. Courtesy of Ford Motor Company.
A cast-iron carrier forms the center of the axle housing. steel axle tubes are pressed into both sides of the carrier to form the housing. the housing and carrier have a removable rear cover that allows access to the differential assembly. because the carrier is not removable, the differential components must be removed and serviced separately. for many operations, a case spreader must be used to remove the components.
A case spreader. Courtesy of General Motors Corporation - Service Operations.