Dealer and Service Glossary

Most of the leverage in a dealership conversation comes from knowing what the words on the page mean. These are the terms that show up on quotes, contracts, and repair orders, defined the way an owner needs them rather than the way a brochure uses them.

Pricing and paperwork

Out-the-door price

The total amount you pay, including price, all fees, and taxes. The only number worth comparing between dealers.

Documentation fee

A charge for processing paperwork. Capped by law in some states and unregulated in others. Frequently negotiable in practice regardless of what you are told.

Destination or freight

The cost of shipping from factory to dealer. Legitimate and generally non-negotiable, but it should appear once, not twice under two names.

PDI (pre-delivery inspection)

The setup and inspection performed before handover. On equipment and RVs, ask for the completed checklist as a document.

Due bill

A written promise on the purchase agreement to perform work or supply an item after delivery. The only form in which a post-sale promise is worth anything.

ADM or market adjustment

An amount added above list price during high demand. Always negotiable, because it is discretionary by definition.

Amount financed

The principal you are actually borrowing after down payment and trade. Compare this rather than the monthly payment.

Gap coverage

Pays the difference between a loan balance and an insurance settlement after a total loss. Sometimes sensible, usually cheaper from your own insurer.

Service and repair

Flat rate

Labor billed from a published book time rather than actual hours. Why a shop can usually quote labor on a common repair before starting it.

Diagnostic fee

Charge for identifying a fault. Ask whether it is credited toward the repair if you proceed, and insist on written findings.

TSB (technical service bulletin)

Manufacturer guidance on a known issue and its approved fix. Powerful support for a goodwill request, because it establishes the failure is recognized.

Goodwill

Discretionary repair assistance outside written warranty terms. Granted more often than owners expect, especially with documented service history.

OEM, aftermarket, remanufactured

Original manufacturer parts; third-party equivalents; and rebuilt originals. All three can be appropriate. What matters is knowing which you are being billed for.

Core charge

A deposit on a rebuildable old part, refunded when it is returned. Why the shop sometimes cannot hand you the failed component.

Shop supplies

Consumables such as solvent and rags. Reasonable as a capped charge, questionable as an uncapped percentage of the invoice.

Mechanic's lien

A shop's right to retain a machine until a bill is paid. The reason authorization limits matter more before work begins than after.

Tractors and equipment

PTO (power take-off)

The splined shaft transferring engine power to an implement. Rated by speed and horsepower, which must match the implement.

Three-point hitch

The standardized implement mount at the rear of a tractor. Sized in categories; a category mismatch means an implement will not fit properly.

Hydraulic remotes

Auxiliary hydraulic outlets for implement functions. Count them before buying an implement, because adding remotes later is expensive.

Hydrostatic transmission

Fluid-driven drive with infinitely variable speed. Easier to operate, generally less efficient than gear drive under sustained heavy load.

Engine hours

The primary wear measure on equipment. Verify the meter reading against the sales documents and service history.

DPF (diesel particulate filter)

Emissions component that traps soot and periodically regenerates. Chronic short-duration, light-load use causes most DPF complaints.

RVs and trailers

GVWR

Gross vehicle weight rating — the maximum permitted loaded weight. Not a target; a legal and mechanical ceiling.

Payload capacity

What you may actually add: passengers, cargo, water, and propane. Commonly exhausted faster than owners expect once tanks are full.

Tongue or pin weight

Downward force the trailer places on the hitch or bed. Must fall within both the hitch rating and the tow vehicle's limits.

Dry weight

Weight as built, without fluids, cargo, or dealer-added options. Nearly always lower than how the unit will actually travel.

House battery

The bank powering living systems, separate from the chassis starting battery. Capacity and type determine off-grid usability.

Delamination

Separation of sidewall layers, usually from long-term water intrusion. Expensive, often structural, and a primary reason to inspect roof seals.

Breakaway switch

Safety device applying trailer brakes if it separates from the tow vehicle. Test it at delivery rather than assuming it works.