4x4 Vans : Quigley Motor Company, Inc. > Technical Center > Glossary of Terms

Glossary of Terms                                 Contact Us

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Abbreviation for Four-Wheel Drive


Anti-Lock Brake System

Metal sleeve that connects the two ends of the tie-rod together. Used to adjust for alignment specifications. There is also an adjusting sleeve on the drag link which is used to align the steering wheel.

Simply put, an AXD differential uses an electronic signal to engage the half axle shafts on the IFS system. We use a AXD differential on the Quigley 2003 and later IFS system. The AXD is electronically driven "sleeve" couplilng that when engaged, it slides over the two half axle shafts, thus locking them into the differential's spider gears. The differential then supplies the torque and momentum used to drive the wheels. The AXD coupler serves as your hub locks on the solid axle system. It can be considered as an automatic hub lock since it is engaged by an electronic signal sent from the shift lever of the transfer case.

The axle receives the torque from the drive shaft, which then displaces the torque to the wheels. This sets the wheels in motion.

A 4x4 vehicle consists of two axles, the front and rear. The front axle can either be a solid axle, as is the rear, or can consist of two axle halves, as with the IFS 4x4 system.

In an IFS system, the axle doesn't consist of one solid, rigid metal casing. It is divided into two separate axle shafts. Each axle is commonly referred to as an Axle Half or Half Axle Shaft.


Connects the steering knuckles to the axle on the solid axle and for the IFS system, it connects the upper and lower control arms to the steering knuckle.

A brake caliper, or just a caliper, is the "muscle" of the brake system.

This mechanism also houses the brake pads or shoes and the ABS control valve. It receives fluid from the master cylinder, forcing the brake pads or shoes against the rotor, causing the rotors to slow and/or stop.

A friction bearing part that clamps down onto the rotor, causing the rotor to slow and/or stop.


This is an incomplete vehicle that consists of only the cabin, occupants compartment, and requires the addition of cargo-carrying, work-performing or load-bearing components to perform its intended function.

Connects or "links" each tie-rod together on the IFS. It is the center connection of the two tie-rods. It is mounted by both the Pitman Arm and the Idler Arm. It serves the same purpose for the IFS system as the Drag Link does on the solid axle conversion.

The point at which the entire weight of the vehicle may be considered as concentrated so that if supported at this point, the vehicle would remain in equilibrium. 

Also known as the "A-Arm". The suspension component that holds the Steering Knuckles to the frame.

Constant Velocity Joint


Houses the gears of the axle. The axle shafts mate to the gears inside the differential. The differential is also referred to as the "Pumpkin".

Connets the Pitman Arm to the tie-rod or right steering knuckle.

This is how the steering is transferred from the steering box to the steering knuckles.

A cylindrical metallic tube that delivers the torque from the Transfer Case to the axles.

Serves as protection, especially for the fuel tank, just in case the drive shaft breaks. It will contain the shaft and keep it from hitting parts under the vehicle's body.

An axle that contains two wheels & tires on each side.


Front Gross Axle Weight Rating. Also referred to as GAWR Front. This is the maximum load that the front axle and suspension can handle.

Federal Motor Vehicle Safety Standards. These are guidelines and laws set in place by the U.S. Federal Government. All motor vehicles must adhere to these standards.


Gross Vehicle Weight Rating. This is the maximum weight that a vehicle can handle, including passengers, full fluids, and load weight.


Where the passenger's hip, the pivot joint of the torso and thigh, would be located when in the seated position. Every seating position has a measurement called the hip point. QMCI defines this measurement as the distance from the driver's hip to that of the seating position being measured. 

Note that the front passenger, directly to the right of the driver, has the same hip point of the driver. The drive'rs hip point is already given by the manufacturer.

Houses the wheel bearings. On the Ford axle, the hub assembly is bolted directly to the steering knuckle, however with the Dana axle the hub is mounted on the spindle.

Locks the wheel hub to the axle shaft. This is how the torque is supplied to the wheels when placed in four-wheel drive. When the hub lock is in the free position, the wheel rotates free of torque from the axle.


Steering component that serves as a mounting surface between the frame and the Center Link on the IFS system. Looks like the Pitman Arm but is on the opposite side of the Pitman Arm.

Independent Front Suspension


A tapered, threaded stud connecting the axle to the steering knuckle on the Dana style axle.


The nut that fastens the wheel to the rotor.


Short for Multiple Passenger Vehicle. This is defined as a vehicle that carries more than two, but less than ten passengers. A vehicle with two or less is commonly referred to as a truck. Any vehicle with ten or more passengers is referred to as a bus.


Rear Gross Axle Weight Rating. Also referred to as GAWR Rear. This is the maximum load that the rear axle and suspension can handle.

Provides the surface area for the brake pads to engage.

On the Ford axle, they are held to the hub by the lug nuts. On the Dana axle, the rotor is pressed onto the hub by the wheel studs.


Any seat inside the vehicle that can be occupied while the vehicle is in motion. In other words, it is a seat that has a seat belt associated with it.

Safety components that maintain vertical loads placed upon tires to help keep the tires in contact with the road. Shocks do not support the weight of the vehicle, but are a major component in the suspension system which controls the suspension movement.

A rear axle that has only one wheel and tire on each side.

A type of yoke that can slide (slip) over splines to allow the axle or drive shaft to vary in length.

On the Dana axle, the spindle connects the hub to the steering knuckle. It also has the brake caliper mount.

A suspension component which absorbs and/or releases energy to counteract the vertical movement of the vehicle. Also provides support for the weight of the vehicle.

A hydraulic gear box that transfers the motion of the Steering Wheel to the Pitman Arm.

Dealers who have made a commitment to stock Quigley vehicles on their lot.

Helps to reduce the "rolling" effect of the vehicle from one side to the other.


Connects (ties) both steering knuckles together.

Connects the axle to the frame on a solid axle 4WD system.

Suspension spring.

Keeps the axle from moving (tracking) in a side-to-side motion.

Transfers the torque from the transmission to the front and rear drive shafts and increases the engine torque on the wheels.

Joins (adapts) the transfer case to the transmission.


Unloaded Vehicle Weight


Vehicle Identification Number


A rotating mechanism which supports the wheel hub, allowing the wheels to rotate freely.

Threaded bolt that the lug nut is screwed onto. They are pressed into the hubs.

The distance between each axle's center.


Any type of structure that spans (crosses) between two pieces and supplies support for another part or mechanism.


A type of union joint that connects the drive shaft to the axle and to the transfer case.