--- slug: semi-truck-and-trailer-tires title: "Semi Truck and Trailer Tires: What a Tire Inspection Covers" description: "Semi truck and trailer tires as one system of tires, wheels, valve stems, inflation and wheel ends, and what a commercial truck tire inspection covers." track: maintenance kind: article isRegulatoryAdjacent: false publishedAt: 2026-10-22 source: https://shopbluecollarparts.com/kb/semi-truck-and-trailer-tires license: CC BY 4.0 --- # Semi Truck and Trailer Tires: What a Tire Inspection Covers Semi truck and trailer tires, from the steer tires on the tractor to the semi trailer tires on each trailer axle, are one part of a system. That system also includes the wheels, the valve stems, the inflation equipment and the wheel ends the tires turn on. A commercial truck tire inspection looks at all of them, position by position. This page is an overview. Each section links to a page that goes deeper. ## What is in the tire and wheel system? 1. **Tires, by position.** A tractor has steer tires on the front axle and drive tires on the drive axles. A trailer has trailer tires on each trailer axle. Most drive and trailer positions run duals, two tires side by side, though some run a single wide-base tire in place of a dual pair. Tires are made for a position, and the tire manufacturer says which positions a tire is built for. 2. **Wheels.** The wheel the tire is mounted on, most often a disc wheel, and the studs and nuts that clamp it to the hub. How a wheel mounts, and the nut torque that goes with it, comes from the wheel manufacturer's documentation. 3. **Valve stems.** Each tire's valve, its cap, and on inner duals often an extension or a hose that brings the valve to where a gauge can reach it. 4. **Inflation.** The air pressure each tire runs at, and, on many trailers, an automatic tire inflation system that adds air to a tire that is losing it. See [semi truck tire pressure and trailer tire inflation](/kb/semi-truck-tire-pressure-and-inflation). 5. **Wheel ends.** The hub, bearings and seal the wheel bolts to. See [wheel seal leaks and replacement](/kb/wheel-seal-leaks-and-replacement) for tractor steer and drive axles, and [trailer wheel end maintenance](/kb/trailer-wheel-end-maintenance) for trailer hubs. ## What does a commercial truck tire inspection cover? A tire inspection typically covers these categories at each position. The customer's program and the manufacturers' documentation define the detail: - **Inflation pressure**, measured with a gauge and compared with the pressure the tire should run at for its load. See [semi truck tire pressure and trailer tire inflation](/kb/semi-truck-tire-pressure-and-inflation). - **Tread depth**, measured with a tread depth gauge in the tread grooves. See [truck tire tread depth and condition](/kb/truck-tire-tread-depth-and-condition). - **Tread and sidewall condition**: wear that is uneven across or around the tire, and cuts, bulges, punctures or other damage to the tread or sidewall. - **Duals**: whether the two tires of a dual pair are a match for each other, and whether anything is caught between them. - **Valve stems, caps and extensions.** - **Wheels and wheel nuts**: cracks or damage to the wheel, and missing, damaged or loose-looking nuts and studs. - **Wheel ends**: lubricant on the wheel, the hub cap or the tire that points to a leaking seal. An inspection records condition. It does not decide on its own whether a tire is replaced. What the inspection found, and what was done about it, belongs in the record for the customer. See [recording a tire and wheel service](/kb/recording-a-tire-and-wheel-service). ## Where each tire and wheel page goes - [Semi truck tire pressure and trailer tire inflation](/kb/semi-truck-tire-pressure-and-inflation): where the right pressure comes from, checking it cold, and how trailer automatic tire inflation systems work. - [Truck tire tread depth and condition](/kb/truck-tire-tread-depth-and-condition): measuring tread depth by position, steer tire tread depth, irregular wear and sidewall damage. - [Wheel seal leaks and replacement](/kb/wheel-seal-leaks-and-replacement): what a leaking wheel seal looks like on steer and drive axles, and what hub oil seal replacement involves. - [Recording a tire and wheel service](/kb/recording-a-tire-and-wheel-service): what to put in the record the customer receives. On a trailer, tires are one of several systems. See [semi trailer maintenance](/kb/semi-trailer-maintenance) for the rest, and [trailer wheel end maintenance](/kb/trailer-wheel-end-maintenance) for trailer hubs. ## Is a tire inspection the same as a DOT inspection? No. A tire inspection done as maintenance records the condition of the tires and the work done. It is not a federal annual inspection, it does not decide whether a vehicle is out of service, and it is not evidence of compliance. The annual inspection standard covers tires too. See [Appendix A inspection standards](/kb/appendix-a-inspection-standards) for that standard, [PM inspection vs. DOT inspection](/kb/pm-inspection-vs-dot-inspection) for the difference, and [FMCSA out-of-service checks](/kb/fmcsa-out-of-service-checks) for what roadside inspectors cite. ## Use the manufacturer's documentation Pressures come from the tire manufacturer's load and inflation tables. Wheel nut torque comes from the wheel manufacturer. Seal installation comes from the seal manufacturer, and bearing adjustment from the hub or axle manufacturer. This page names where each specification lives and does not state one. Confirm every value against the documentation for the specific tire, wheel or hub on the vehicle. ## Log the work in Blue Collar Parts A technician who inspects or services tires and wheels can log the work in Blue Collar Parts and send the record to their customer, who confirms it. [Learn what Blue Collar Parts is](/kb/what-is-blue-collar-parts). --- *This page describes semi truck and trailer tires and wheels in general terms. It is not a service manual and does not establish regulatory compliance. Use the tire, wheel and equipment manufacturers' current documentation for specifications and procedures.* ## Sources What BCP does here: Blue Collar Parts records the work and sends the report to your customer. It does not perform, certify or approve inspections. Reviewed 2026-10-22