|
|
|
|
| |
If the steel becomes too hard, it can be softened, or annealed, to a desirable hardness. This is done by heating to a predetermined point (according to the material) followed by a slow cooling. This process is also used to relieve the internal stresses in a part. |
|
|
|
|
| |
The carrier, or carrier case, is the unit which the ring gear bolts to and axles slide into. The carrier case transfers power from the ring gear to the axles. |
|
|
|
|
| |
This is a process where the outer shell or case of the metal is hardened only to a precise and predetermined depth. |
|
|
|
|
| |
A C-clip is a semi-circular retaining clip used to hold semi-float axles in the housing. With the cross spin shaft removed, the axle can be pushed into the housing far enough for the C-clip to be installed into a groove on the end of the axle splines. The axle is then pulled back outward until the C-clip seats into a groove in the side gear. The cross pin shaft is then installed, preventing the axle from moving inward and the C-clip from falling out. |
|
|
|
|
| |
This is a hardened shaft which installs into the case and keeps the spiders securely in place. In semi-float applications, it also prevents the axles from sliding inward into the carrier case. |
|
|
|
|
| |
This is a commonly used term for the ring gear. |
|
|
|
|
| |
This is a collapsible spacer which installs on the pinion and preloads the pinion bearings. Crush sleeves are not reusable and must be replaced if the pinion nut is loosened or removed. |
|
|
|
|
| |
This is the opposite of heat treating and it’s done to a part that is generally finished, such as a complete axle shaft. The part is cooled by normal refrigeration to about 100 degrees below zero, Fahrenheit, then further cooled by nitrogen gas to about 300 degrees below zero. The timing and length of the treatment is precisely controlled according to the material and the end result desired and, after cooling, the part is heated to over 300 degrees then allowed to cool naturally in the air. The advantages are that it relieves internal stress in parts and tightens the grain structure. The treated part is much more fatigue resistant, though only very slightly stronger. Dimensional changes are usually miniscule or non-existent. |
|
|
|
|
| |
A drop out is a type of differential housing in which the gear case assembly can be removed from the housing. Other differential housings simply have inspection covers which are removed, allowing you to work on the differential inside the housing. The advantage of a drop out style housing is the ability to work on the differential on a bench. |
|
|
|
|
| |
This is divided into two categories, hot forging and cold forging. Hot forging is done when the metal is red hot and soft. Cold forging is done with the metal no hotter than 1/3 its melting point. In both cases, the metal is worked under high pressure (usually a giant press or hammering machine) to tighten the grain structure of the steel and make it stronger. Often the steel is formed into a particular shape at the same time. |
|
|
|
|
| |
A full floating axle is a housing type in which the axle does not carry the load of the vehicle and does not have the wheel bolt directly to it. Full floating axles bolt to a spindle, which ultimately drives the wheels. |
|
|
|
|
| |
High pinion refers to a housing where the pinion enters above the centerline. This is also called a “reverse-rotation” housing. High pinion housings are only found in the fronts of some factory vehicles. |
|
|
|
|
| |
This stands for “Independent Front Suspension”, a housing which allows the left and right axles to move up and down separately from each other. |
|
|
|
|
| |
This stands for “Independent Rear Suspension”, a housing which allows the left and right axles to move up and down separately from each other. |
|
|
|
|
| |
This is a method of case hardening. It’s a common hardening method for axles because it’s fast and can be localized and controlled. Typically, electromagnetic coils are used and the part is heated to a precise temperature and for a precise time, sometimes in several cycles, then instantly cooled. The beauty of induction hardening is that the depth of the hardening can be very precisely controlled.
|
|
|
|
|
| |
A limited slip differential is a type of carrier case where the spider gears are preloaded and prevented from turning easily via a friction surface. Once enough power has been applied to the spiders, which is called a breakaway point, the spiders can turn. The preload and friction can sometimes cause noise or “chatter” when negotiating a turn. |
|
|
|
|
| |
A locker is a mechanical ratcheting unit that drives both tires when under power. A locker does allow one side to disengage when turning, often resulting in a “banging” or “clunking” sound. |
|
|
|
|
| |
Nitriding is a surface treatment that case hardens metal. The part is heated in a closed environment with a nitrogenous material, usually ammonia. The surface absorbs nitrogen and becomes harder. Much harder surfaces can be obtained than with other case hardening processes.
|
|
|
|
|
| |
The pinion gear turns the pinion gear, transferring power from the driveline. |
|
|
|
|
| |
Pinion preload is the amount of resistance or “drag” measured when attempting to turn the pinion without the carrier installed. |
|
|
|
|
| |
The pinion yoke attaches to the pinion gear to the driveshaft. |
|
|
|
|
| |
This is commonly used term for a limited slip. |
|
|
|
|
| |
The ring gear bolts to the carrier and is driven by the pinion gear. |
|
|
|
|
| |
A semi-floating axle rides on an outer bearing, thus supporting the weight of the vehicle. In semi-floating applications the wheel is bolted directly to the axle. |
|
|
|
|
| |
A shim is a thin piece of metal that is used to either adjust the fitment of other parts or take up a gap. |
|
|
|
|
| |
The side gear fits into the housing and has splines on the inside which accepts the axle splines. Side gears are part of the spider gear set. |
|
|
|
|
| |
The spider gears are a set of four to six gears which install into the carrier. The rotation of the spider gears allows one axle to spin faster or slower than the other. |
|
|
|
|
| |
A third member is a type of differential housing in which the gear case assembly can be removed from the housing. Other differential housings simply have inspection covers which are removed, allowing you to work on the differential inside the housing. The advantage of a drop out style housing is the ability to work on the differential on a bench. |
|
|
|
|
| |
The entire part is hardened to a uniform standard by heating and cooling according to a precise timetable and temperature chart. |
|
|
|
|
| |
This is a method where flanges are forged onto the end of metal bar stock that will become an axle. Typically, the bar is near its melting point. It goes into a press, the shaft is clamped in a die at a particular point and the portion above the die is tooled into the desired shape. It not only produces the flange but hardens it to a desirable point. Often, the flange area receives no further hardening. |
|
|