RV Glossary Terms
120 AC/12 DC/LP Gas
The power source that runs the RV refrigerators; 120 AC is 120-volt alternating current; 12 DC is 12-volt direct current; LP-gas. Some RV refrigerators can operate on multiple sources.
Adjustable Ball Mount
Allows the ball to be raised, lowered and tilted in small increments to fine tune the spring bar and compensate for tow vehicle "squat," which happens when the trailer coupler is lowered onto the ball.
A shock absorber at the front and rear axles of a motor home.
An RV designed for the colder climates.
A roof-like structure made of canvas or other artificial materials which extends from the RV body to provide shade. Awnings are generally placed over entrances. Some extend and stow manually while others are operated electrically.
The number of times the drive shaft must turn for the axle to tun one time. If you have a 4:1 axle ratio, the drive shaft turns 4 times for every turn of the axle. The higher the number, the more pulling power you have and the more gas you will burn.
A slot in an RV park with a single entrance, designed to be backed into with the RV.
The part of the hitch system that supports the hitch ball and connects it to the trailer coupler. Ball mounts are available in load-carrying and weight-distributing configurations.
Refers to storage area accessible from the outside, usually from the door threshold area down.
TV antenna, on the roof of an RV, characterized by two horizontal elements. Batwing antennas are generally raised and rotated with a hand crank from within the RV living compartment.
Holding tank of an RV for storing toilet waste.
Water, from a toilet system, held in an on-board holding tank until a means of disposal is available.
Term for portable waste holding tank. This plastic tank often comes in a bright shade of blue, hence the term.
Camping without using the modern conveniences of hooking up to electric, sewer or water. Also implied for folks staying at a campground; but due to short length of stay, they do not hook-up to the utilities even though these utilities are provided.
Reference to the "living space" on a class A motor home, built from the chassis up.
Device mounted under the dash of a tow vehicle to control the braking of the trailer.
A control unit mounted inside the vehicle that allows electric trailer brakes to become activated with the braking of the tow vehicle.
Refers to a brake system for a "towed" vehicle. Required in many states and Canadian provinces and definitely an add-on safety feature.
Refers to a system that allows the "towed" vehicle to break-away from the towing vehicle in the event of an accident; an add-on safety feature.
BTU (British Thermal Unit)
A measurement of heat required to raise the temperature of one pound of water one degree Fahrenheit. RV air-conditioners and furnaces are BTU-rated.
Loose term for defining a variety of conditions; such as when describing the level of RV sitting.
a term used to describe a condition where the front axle feels to be rapidly bottoming out on the jounce bumpers and transferred back through the steering column and steering wheel. There can be several different causes to this problem with different cures for each condition. Sometimes, a simple fix such as shocks or a steering stabilizer; sometimes more detailed corrections are needed for correcting serious manufacturing oversights.
Slang term regarding the hitch or towing method for a conventional travel trailer or pop-up; receiver and ball-mount type hitch.
An RV area containing bunk beds instead of regular beds.
Overlapping top of a Class C motor home. General sleeping area in older models and storage or entertainment area in newer models.
Camber Wheel Alignment
Camber angle is the angle made by the wheel of an automobile; specifically, it is the angle between the vertical axis of the wheel and the vertical axis of the vehicle when viewed from the front or rear. It is used in the design of steering and suspension.
Another term for an RV, especially smaller RV's that are towed behind or carried on top of light trucks. truckers generally refer to all RV's as "campers" in their CB conversations.
Removable camper made to fit in the bed of a pickup truck.
Toilet with a small holding tank that can be removed from outside the vehicle in order to empty it.
Castor Wheel Alignment
Steering wheel's tendency to return to center after the driver turns a corner.
Citizens Band radio is a general use, short distance, two-way radio primarily used by truckers. CB's are also helpful to RV drivers to call for help in an emergency and listen for driving conditions. Many CB's on the market today also have weather channels with alerting features.
CCC (Cargo Carrying Capacity)
Maximum weight of everything you are carrying in your RV.
Battery in a motor home for operating 12 volt components of the drivetrain.
Class of motor home referring to motor home (box) built on chassis frame up.
Class of motor home referring to conversion vans.
Class of motor home referring to RV built using van-type chassis and cab.
The result of warm moisture-laden air contacting cold window glass. Keeping a roof vent open helps to reduce the humidity levels.
Turns AC power to DC power, very useful for your RV.
What attaches your trailer to your vehicle's hitch.
A piece of furniture arranged across the RV from side to side rather than front to rear.
RV with automotive fluids, fuel, oil and coolant, but no water in the holding tanks.
When a fiberglass panel starts peeling off the RV, usually because of water damage.
Demand Water Pump
The water pump that keeps your water system pressurized.
A booth-like dining area in which the table may be lowered to convert into a bed.
Term for a "towed vehicle", also known as "toad".
Also known as "boondocking", camping without hooking up to modern utilities provided at most campgrounds, such as: water, septic/sewer and electricity.
Weight of RV without adding fluids in storage holding tanks or by loading personal effects.
DSI (Direct Spark Ignition)
The method of igniting the main burner on a propane-fired appliance. The burner is lit with an electric spark and the flame is monitored by an electronic circuit board. This ignition system is used in refrigerators, furnaces and water heaters.
Dual Electrical System
RV equipped with lights, appliances which operate on 12-volt battery power when self-contained, and with a converter, on 110 AC current when in campgrounds or with an on-board generator.
A truck with two tires for each side of the rear axle.
Ducted A/C and Heat
A system for air conditioning in an RV; the cool air goes through the ceiling and the heat through the bottom.
Air conditioning supplied through a ducting system in the ceiling. This supplies cooling air at various vents located throughout the RV.
Warm air from the furnace supplied to various locations in the RV through a ducting system located in the floor.
Place where holding tanks can be emptied either by paying a small fee or free.
Attractive price for first-time RV buyers of generally lower-cost RVs.
A hitch that distributes some of the weight across your trailer as well as your towing vehicle, usually 10 to 15 percent.
A normally open switch that closes at a preset temperature. It causes the furnace to run for a short time after the thermostat opens, allowing the furnace to cool down.
Fifth Wheel Trailer
A trailer with a raised front that extends over the bed of a pickup truck. There a special hitch in the truck bed to attach it.
Fiberglass sheeting used in RVs with fiberglass sidewall construction.
Final Drive Ratio
The reduction ratio found in the gear set that is located farthest from the engine. This is the same as the axle ratio.
Another name for fifth wheel.
Slang for towing a vehicle with all four wheels down on the ground.
Holding tank on RV for storing fresh water.
Fresh Water Fill
Where you load fresh water into your RV.
Term for campground accommodations offering water, sewer/septic and electricity.
Someone who travels/lives in a recreational vehicle most of the year.
The kitchen of an RV.
Angled tub with wide edges around corners for bathroom items.
Sofa/dinette bench that converts into a sleeping unit; a term less used now than formerly.
GAWR (Gross Axle Weight Rating)
The maximum allowable weight each axle is designed to carry, as measured at the tires, therefore including the weight of the axle assembly itself.
GCWR (Gross Combined Weight Rating)
The maximum allowable combined weight of the tow vehicle and the attached towed vehicle. GCWR assumes both vehicles has functioning brakes, with exceptions in some cases for very light towed vehicles, normally less than 1, 500 pounds.
Brand name for an auxiliary transmission designed to give the driver control of the vehicle's gear ratio and being able to split gears for peak performance and at the same time have an overdrive.
Gas or propane powered engine for generating 120-volt AC power when the RV is not connected to an electrical power source.
Abbreviation for generator set.
A colloquial name for fifth-wheel travel trailers.
A device that attaches to the fifth wheel trailer's king pin and extends down about two feet. It couples with a ball hitch mounted in the bed of a truck, enabling the fifth wheel to be towed like a gooseneck trailer.
The degree of inclination of a road. A grade of 6% or higher is considered steep.
Disposal water from sinks and shower. In some units, this is held in a holding tank separate from black water.
Holding tank of RV for storing used dishwater/bathing water.
GTW (Gross Trailer Weight)
Gross trailer weight is the weight of the trailer fully loaded in its actual towing condition. GTW is measured by placing the fully loaded trailer on a vehicle scale. The entire weight of the trailer should be supported on the scale.
GTWR (Gross Trailer Weight Rating)
Maximum allowable weight of a trailer, fully loaded with cargo and fluids.
GVWR (Gross Vehicle Weight Rating)
The maximum allowable weight of the fully loaded vehicle, including liquids, passengers, cargo, and tongue weight of any towed vehicle.
Truck rating originally conceived to indicate cargo carrying capacity of a half ton (1,000 lbs). Today, tonnage rating is no longer an accurate indication of cargo carrying capacity. It is more of a relational indication among trucks in different categories. Common one ton pickup truck models are the Chevrolet 1500, Dodge 1500, Ford F-150, and GMC 1500.
RV walls made of aluminum or other hard surface.
Truck body installed on a chassis in place of a bed, designed to tow or haul various loads. Most hauler backs look like a typical car wrecker without the lift. Hauler backs intended for RV towing have a flat surface and a hitch installed above the rear axle. Common options added to hauler backs are storage compartments and tool boxes.
A heat exchanger is a device that transfers heat from one source to another. For example, there is a heat exchanger in your furnace - the propane flame and combustion products are contained inside the heat exchanger that is sealed from the inside area. Inside air is blown over the surface of the exchanger, where it is warmed and the blown through the ducting system for room heating. The combustion gases are vented to the outside air.
An electric heating element located in the air conditioning system with the warm air distributed by the air conditioner fan and ducting system.
A fifth-wheel trailer with a higher-than-normal front to allow more than 6 feet of standing room inside the raised area.
The fastening unit that joins a movable vehicle to the vehicle that pulls it.
Where you connect your RV to your tow vehicle.
The amount of a trailer's weight that rests on the tow vehicle's hitch.
Holds the black (toilet) and gray (sink, shower, and lavatory) water. Their capacity determines how long an RV can be used without hookups.
Euphemism for the sewage pumping truck. Honey wagons are used to empty RV holding tanks in places where full hookups and dump stations are not available.
Campground facilities provide for connecting an RV to 120-volt, AC shore power, water, sewer, cable TV, and telephone service. Full hookups: refer to water, electricity and sewer at an RV site.
Battery or batteries in motor home for operating the 12 volt system within the motor home, separate from the chassis.
Term used for a type of dirt skirt accessory some RVers use on the back of their motor home to aid in the protection from debris thrown from their rear wheels to the vehicles directly behind them or being towed behind them. This dirt skirt is usually the length of the rear bumper and resembles a 'short' version of a Hawaiian 'hula-skirt', hence the term.
Term for fifth wheel or travel trailer that has been manufactured to be "different" than the standard interior living box. Usually by having pop-out ends over bedrooms that give a "tent" like area for sleeping.
Similar to a spark plug. There are two versions; a three probe (remote sense) and a two probe (local sense).
Converts 12vDC to 12vAC for use with appliances.
A queen-sized bed with walking space on both sides.
A 90% angle obtained from turning/backing fifth wheel or travel trailer with tow vehicle. Jackknifing a short bed truck towing a fifth wheel without the use of a slider hitch or extended fifth wheel pin box can result in damage to the truck cab or breaking out the back window of the truck cab from the truck and fifth wheel "colliding".
The pin by which a fifth wheel trailer attaches to the truck. It slides into the fifth wheel hitch and locks in place.
King Pin Weight
King Pin Weight (also called Pin Weight) is the actual weight pressing down on the fifth wheel hitch by the trailer. The recommended amount of King Pin Weight is 15%-25% of the GTW.
A measurement of electrical power; each kilowatt equals 1,000 watts.
A sandwich of structural frame members, wall paneling, insulation and exterior covering, adhesive-bonded under pressure and/or heat to form the RV's walls, floor and/or roof.
The landing gear on a fifth-wheel trailer are two jacks that are usually coupled together and are motor driven. Landing gears lift the front of the fifth-wheel trailer up so that the truck can be driven under the front and hitch-up. Once hitched up, the landing gear jacks are raised to their stowed position for traveling.
Positioning the RV in camp so it will be level, using ramps (also called levelers) placed under the wheels, built-in scissors jacks, or power leveling jacks.
A jack lowered from the underside of trailers and motor homes for the purpose of leveling the vehicle. A leveling jack is designed to bear a significant portion of the RV's weight, even lifting it off the ground on certain models.
Light Weight RV
Recreational vehicles that are designed to easily be towed behind most SUVs, minivans, light-duty trucks and some cars.
A furnace safety switch that is normally closed but that opens if it gets to hot. When it opens, it turns off the power to the gas valve and igniter board.
A differential that is designed with a mechanism that limits the speed and torque differences between its two outputs, ensuring that torque is distributed to both drive wheels, even when one is on a slippery surface.
On rental RVs these items may be rented at an additional cost. Includes bed linens, pillows and blankets, bath towels, pots and pans, kitchen utensils, cutlery.
Liquid petroleum or propane, used for cooking and heat and stored in tanks.
Lets you see how full your water tanks are and also the status of your house battery.
NCC (Net Carrying Capacity)
The maximum weight of all personal belongings, occupants, food, fresh water, LP gas, tools, dealer installed accessories, etc., that can be carried by the RV.
Truck rating originally conceived to indicate cargo carrying capacity of one ton (2,000 lbs). Today, tonnage rating is no longer an accurate indication of cargo carrying capacity. It is more of a relational indication among trucks in different categories. Common one ton pickup truck models are the Chevrolet 3500, Dodge 3500, Ford F-350, and GMC 3500.
Type of RV that is usually designed for permanent parking but is shorter in length than a traditional mobile home. All the amenities of a mobile home but not built for recreational travel.
People who use their RV for longer than normal vacation time but less than one year.
Carpet or woven mat for use on ground outside of RV. Used whether or not a concrete patio pad is available where camping.
The maximum allowable weight that can be placed in or on a vehicle, including cargo, passengers, fluids and fifth-wheel or conventional hitch loads.
A small standby flame used to light the main burner of propane fired appliance when the thermostat calls for heat. Pilots can be used in furnaces, water heaters, refrigerators, ovens and stove tops.
Term for a RV campground "get-together", usually means "pitching-in" a covered dish or casserole.
Abbreviation for "pop-up" camper.
Term for room or area that 'pops-out' for additional living space in RV. This type of expanded living area was more common before the technology of slide-out rooms became popular and available.
Folding camping trailer.
Used to describe the movement of an RV while traveling; it goes up and down, like a dolphin swimming.
Camping without the modern convenience of full-hookup facilities of city/well water, sewer/septic and electricity. Primitive campers rely on 'on-board' systems for these conveniences; generator, batteries, stored water, etc.
Term for a camping space (whether in campground or not) that only requires the driver to "pull-through" or "drive-through" to access the camping spot, and upon leaving you again just drive forward to leave or exit the camping space.
Slang for front engine motor home. Term most often used to refer to front mounted diesel engine motor homes.
Slang for rear engine motor home. Term most often used to refer to diesel engine motor homes.
A set of gears found in the rear axle of vehicles, designed to distribute drive shaft power to the two wheels. It applies power to both wheels while allowing each to spin at different rates during cornering.
The portion of a hitch that permits a hitch bar or shank to be inserted. The receiver may be either 11/2-, 15/8- or 2-inch square.
Slang for "refrigerator". Refrigerators are often found in either a "two-way" or "three-way" operating mode. Two-way: Have a gas mode and an AC mode. Three-way: has a gas mode, AC mode, and 12v DC mode. The coolant used in RV refrigeration is ammonia.
Gas controls for your appliances.
Term used to describe a lack of ability to maintain the motor home in a straight, forward travel without constant back and forth motion of the steering wheel.
Roof Air Conditioning
Air conditioning unit mounted on roof of RV, to cool the RV when it is parked. When moving, most RVs are cooled by separate air conditioning units which are components of the engine, or they may be cooled by a roof top if a proper size generator is installed.
Short for "recreational vehicle".
Chains connected between the trailer and the tow vehicle so if the hitch breaks, the trailer won't be a hazard.
Term for screen enclosure that attaches to the exterior of a RV for a "bug free" outside sitting area. Some screen rooms have a canvas type roof for rain protection as well.
An RV that needs no external connections to provide short-term cooking, bathing, and heating functions and could park overnight anywhere. Self-contained units can also hook up to facilities when at campgrounds.
Sewer Hose Donut
A plastic or rubber ring to get a good seal on your sewer hose. Required at most campgrounds, for obvious reasons.
Also called a hitch bar or stinger, the shank is a removable portion of the hitch system that carries the ball or adjustable ball mount, and slides into the receiver.
The external electrical cord that connects the vehicle to a campground electrical hookup.
Electricity provided by an external plug to external power source.
Term for a type of camper that mounts on a truck bed, because often this type of camper "slides-in" to the truck bed.
Additional living space that "slides-out" either by hydraulics, electricity or manually, when the RV is setup for camping.
Slang for slider-hitch.
Referring to a sliding hitch used on short bed trucks for enabling them to tow fifth wheels, allowing them sufficient clearance to jack-knife the trailer.
Term for someone in a northern climate that heads "south" in winter months.
Telescoping side panels on an RV that can be raised or lowered, usually constructed of canvas or vinyl and mesh netting.
Component parts of a weight-distributing hitch system, the spring bars are installed and tensioned in such a manner as to distribute a portion of the trailer's hitch weight to the front axle of the tow vehicle and to the axles of the trailer.
A jack inserted under or lowered from trailers and motor homes for the purpose of stabilizing the vehicle. A stabilizing jack is not designed to bear a significant portion of the RV's weight, only a small amount to reduce movement during occupancy. Stabilizing jacks are generally found toward the back of trailers, under the king pin of fifth wheels, and under some slides.
Also called a hitch bar or shank, the stinger is a removable portion of the hitch system that carries the ball or adjustable ball mount, and slides into the receiver.
Slang for the sewer hose, constructed from a spiral wire covered with vinyl. One end attaches to the RV piping and the other into the local sewer dump facilities.
SUT (Sport Utility Trailer)
Can be either a fifth wheel or travel trailer with a built in cargo area for ATV's, bikes, motorcycles, mopeds, or other "toys" you want to take with you inside your RV.
Fishtailing action of the trailer caused by external forces that set the trailer's mass into a lateral (side-to-side) motion. The trailer's wheels serve as the axis or pivot point.
Devices designed to damp the swaying action of a trailer, either through a friction system or a "cam action" system that slows and absorbs the pivotal articulating action between tow vehicle and trailer.
A dead axle behind the drive axle that helps support the weight of the overhang and gives you a little more GVW capacity so you don't have to put the full load on the drive axle. Most tag axles are good for supporting 4-5,000 pounds.
The end RV or vehicle in a caravan.
Compacting from front to back and/or top to bottom to make the living unit smaller for towing and storage.
A thermocouple is a device that monitors the pilot flame of a pilot model propane appliance. If the pilot flame is extinguished the thermocouple causes the gas valve to shut off the flow of gas to both the pilot flame and the main burner.
Three Quarter Ton
Truck rating originally conceived to indicate cargo carrying capacity of three quarter tons (1,500 lbs). Today, tonnage rating is no longer an accurate indication of cargo carrying capacity. It is more of a relational indication among trucks in different categories. Common three quarter ton pickup truck models are the Chevrolet 2500, Dodge 2500, Ford F-250, and GMC 2500.
Term for room (generally in older RVs) that "tipped-out" for additional living space once RV was parked. Newer RVs mainly use 'slide-out' rooms.
Term for a "towed" vehicle.
Wheel alignment - Toe is the measure of whether the front of the wheels (looking down from the top) are closer (toe-in) or farther (toe-out) than the back of the wheels.
The jack mounted on the the trailer that supports the front. Used to raise or lower the trailer during hitching.
The weight pressing on the trailer's hitch when fully loaded.
A tank to fill and haul to a dump station if you can't get close enough, designed to be portable.
Term for fifth wheel, travel trailer or motor home with built-in interior cargo space for motorcycles, bikes, etc.
Brakes that are built into the trailer axle systems and are activated either by electric impulse or by a surge mechanism. The overwhelming majority of RVs utilize electric trailer brakes that are actuated when the tow vehicle's brakes are operated, or when a brake controller is manually activated. Surge brakes utilize a mechanism that is positioned at the coupler that detects when the tow vehicle is slowing or stopping, and activates the trailer brakes via a hydraulic system.
Slang for transmission.
An RV that you tow.
Term for three vehicles attached together. Usually a tow vehicle pulling a fifth wheel and the fifth wheel pulling a boat.
Campers placed on the bed of a pickup truck. Very good with off-roading.
The wiring harness that connects the tow vehicle to the trailer, supplying electricity to the trailer's clearance and brake lights, electric brakes and a 12-volt DC power line (to charge the trailer's batteries).
An RV's underfloor surface, which is protected by a weatherproofed material.
UVW (Unloaded Vehicle Weight)
The weight of a vehicle as built at the factory with full fuel, engine (generator) oil and coolants. It does not include cargo, fresh water, LP gas, occupants or dealer installed accessories.
Slang term used by RVers to describe a Walmart.
Water Pressure Regulator
Protects your plumbing system against over-pressurization.
People who own their RV's for weekend and vacation use.
Weight Carrying Hitch
Also known as a "dead-weight" hitch, this category includes any system that accepts the entire hitch weight of the trailer.
Weight Distributing Hitch
Also known as an "equalizing" hitch, this category includes hitch systems that utilize spring bars that can be placed under tension to distribute a portion of the trailer's hitch weight to the tow vehicle's front axle and the trailer's axles.
Termed used by RVers to describe the weight of a RV with all storage and holding tanks full., i.e., water, propane, etc.
The distance between the centers of the primary axles.
A RV that has a width exceeding eight feet.
To prepare the RV for winter use or storage.
Fishtailing action of the trailer caused by external forces that set the trailer's mass into a lateral (side-to-side) motion. The trailer's wheels serve as the axis or pivot point.