Comparison with locking hubs
Although a widely used system, this system is not as efficient as a system with locking hubs. A CAD system spins the axle shafts, spider gears, and side gears in the carrier during normal driving. Locking hubs disengage the axle at the wheels, allowing all of the axle to be at rest during normal driving. Nevertheless, a CAD system still makes for much less drag than having the axle completely locked in (which would spin the axles, differential, driveshaft and part of the internals of the transfer case).
Like locking hubs, the CAD system is designed to improve fuel efficiency of the vehicle. Other, often debated, benefits of CAD systems are reduced vibration, axle wear, and noise, as well as improved steering and drivability.
An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type of axle is referred to as a spindle.
A differential is a gear train with three drive shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others. A common use of differentials is in motor vehicles, to allow the wheels at each end of a drive axle to rotate at different speeds while cornering. Other uses include clocks and analog computers.
A four-wheel drive, also called 4×4 or 4WD, is a two-axled vehicle drivetrain capable of providing torque to all of its wheels simultaneously. It may be full-time or on-demand, and is typically linked via a transfer case providing an additional output drive shaft and, in many instances, additional gear ranges.
Overdrive is the operation of an automobile cruising at sustained speed with reduced engine speed (rpm), leading to better fuel consumption, lower noise, and lower wear. The term is ambiguous. The most fundamental meaning is that of an overall gear ratio between engine and wheels, such that the car is over-geared, and cannot reach its potential top speed, i.e. the car could travel faster if it were in a lower gear, with the engine turning at higher RPM.
A manual transmission (MT), also known as manual gearbox, standard transmission, or stick shift, is a multi-speed motor vehicle transmission system, where gear changes require the driver to manually select the gears by operating a gear stick and clutch.
In mechanical or automotive engineering, a freewheel or overrunning clutch is a device in a transmission that disengages the driveshaft from the driven shaft when the driven shaft rotates faster than the driveshaft. An overdrive is sometimes mistakenly called a freewheel, but is otherwise unrelated.
A limited-slip differential (LSD) is a type of differential gear train that allows its two output shafts to rotate at different speeds but limits the maximum difference between the two shafts. Limited-slip differentials are often known by the generic trademark Positraction, a brand name owned by General Motors and originally used for its Chevrolet branded vehicles.
Quattro is the trademark used by the automotive brand Audi to indicate that all-wheel drive (AWD) technologies or systems are used on specific models of its automobiles.
A transfer case is a part of the drivetrain of four-wheel-drive, all-wheel-drive, and other multiple powered axle vehicles. The transfer case transfers power from the transmission to the front and rear axles by means of drive shafts. It also synchronizes the difference between the rotation of the front and rear wheels, and may contain one or more sets of low range gears for off-road use.
A locking differential is a mechanical component, commonly used in vehicles, designed to overcome the chief limitation of a standard open differential by essentially "locking" both wheels on an axle together as if on a common shaft. This forces both wheels to turn in unison, regardless of the traction available to either wheel individually.
The Dodge Ramcharger is a large sport utility vehicle built by Dodge from 1974 to 1993, based on a shortened-wheelbase version of the Dodge D series/Ram pickup chassis. A Plymouth version, named the Plymouth Trail Duster, offered from 1974 to 1981, was Plymouth's only SUV.
Jeep uses a variety of four-wheel drive systems on their vehicles. These range from basic part-time systems that require the driver to move a control lever to send power to four wheels, to permanent four-wheel systems that monitor and sense traction needs at all four wheels automatically under all conditions.
The following outline is provided as an overview of and topical guide to automobiles:
Super Select is the brand name of a four-wheel drive system produced by Mitsubishi Motors, used worldwide except for North America, where it was initially known as Active-Trac. It was first introduced in 1991 with the then-new second generation of the Mitsubishi Pajero.
ControlTrac four-wheel drive is the brand name of a selectable automatic full-time four-wheel drive system offered by Ford Motor Company. The four-wheel drive system was designed and developed at BorgWarner under its TorqTransfer Systems division in the mid 1980s. BorgWarner calls the system Torque-On-Demand (TOD). ControlTrac was the first automatic system to use software control and no planetary or bevel geared center differential. Instead of a planetary or bevel geared center differential, the system uses a variable intelligent locking center multi-disc differential.
The GM 10.5" 14-bolt differential stands as a robust drivetrain component extensively featured in Chevrolet and GMC trucks, SUVs, and vans from 1973 onward, including specific versions of the Cadillac Escalade. Introduced in 1973, this differential employs a full-floating design, boasting a substantial ring gear diameter measuring 10.5 inches. Its nomenclature, "14-bolt," represents the 14 bolts securing the differential cover, although the ring gear itself is fastened by 12 bolts. Notably, the 14-bolt differential gained traction among Jeep Wrangler owners seeking axle replacement options, earning the moniker "corporate" 14-bolt because of its association with GM's corporate structure during the 1970s.
The Dana/Spicer Model 60 is an automotive axle manufactured by Dana Holding Corporation and used in OEM pickup and limited passenger car applications by Chevrolet, Dodge, Chrysler, Jeep, Ford and Land Rover. There are front and rear versions of the Dana 60. It can be readily identified by its straight axle tubes, 10 bolt asymmetrical cover, and a "60" cast into the housing. Gross axle weight ratings are often lowered by the vehicle manufacturer for safety and tire reasons. They are also lowered to reduce loads on other powertrain components such as transmissions and transfer cases. Dana 60 Axles are also increasingly swapped into many custom offroad applications to accommodate larger tires and deep compound gearing with locking differentials.
A transmission brake or driveline parking brake is an inboard vehicle brake that is applied to the drivetrain rather than to the wheels.
An all-wheel drive vehicle is one with a powertrain capable of providing power to all its wheels, whether full-time or on-demand.
