Axle - An axle is a central shaft for a rotating wheel or gear. The axle transfers power from the differential at the wheels. The axle shafts have grooves at one end fitted into the support and a flange at the other end that holds the wheel studs. Axle Bearings - Axle bearings are pressed on the axles and are retained by the end of the housing. They're held in position by the stop plate and 4 bolts. Axle bearings allow the axles to spin in place when power is applied to them through the differential. Axle Seals - Axle seals are seals that ride on a machined surface on the flanged end of the axle that seals the axle to the end of the housing in order that gear oil can't escape.
When a rear axle seal goes bad, it is typically noticeable by gear oil that leaks over a rear wheel, and it can get into the brake drum and reduce rear brake feel. Bolt Schema - A series of holes made in axle flange face that correspond with a series of holes drilled in the brake drum or rotor that wheel studs press into to allow wheels to bolt to the unit. Carrier Unit - The interior differential component that the ring gear bolts to. This unit transfers power from the driveshaft\/pinion gear to the axles. Carriers can be found in various types which are utilized in different vehicle applications.
Common types are an open carrier, traction lock, Detroit locker, ARB air locker, spool, etc. Drum Brakes - Consists of brake shoes which are mounted to a support plate that bolts to the rear end housing, or in case of older model vehicles can be present on the front axles also. The shoes are housed in a round drum that rotates with the wheel. Disc Brakes - Disc brakes consist of a brake rotor and a caliper. The caliper has friction pads inside it that whenever brake pressure it applied the brake pads squeeze against the rotor to slow the wheel.
When all of the internal differential components are installed into the case, the unit is referred to as a third member. Housing - A steel tube assembly which has the 3rd member receptacle in the center and the axle bearing housings on the ends. This unit spans side to side in the car and requires brackets to be welded to it to fix it to the car. Housing Center - Stamped steel centerpiece of housing that the 3rd member bolt into, and the housing tubes press into. Housing Covers - A plate that covers the back of a housing unit.
Housing Tubes - Tube which goes between the housing center and the housing ends that covers the axle shaft. Housing Brackets - Necessary brackets that weld to the housing and allow for the housing to be screwed into the car. Housing Ends - The end caps that weld to the end of the tubes on the housing which are the receptacle that the axle bearing fits into. Pinion Seal - A seal that fits into the front of the pinion support and seals the outside the yoke to the pinion support. Pinion Support - A flange on the front of the third member that is retained by five 3\/8 bolts.