Trailer tire repair and replacement means fixing a punctured tire properly or fitting a new one of the right size, type and load range, with the trailer right where it sits. Keep Them Rolling Trailer Repair handles flats, worn tires and bent or rusted rims at the trailer in Morris, Sussex, Warren and Hunterdon counties, and owner Brad Smith answers tire calls at (973) 651-1045.
Trailer tire repair or replacement?
Repair is an option when the damage is a small puncture in the tread area and the tire hasn’t been driven on flat. The right way to do it is from the inside: the tire comes off the rim, the inner liner is inspected and prepped, and the hole is filled and sealed with a plug and patch together. A plug pushed in from the outside is a roadside stopgap, not a repair.
The tire gets replaced instead when:
- The puncture is in the sidewall or shoulder, where the tire flexes most
- The hole is too large to repair safely
- The tire was run flat, which crushes and overheats the sidewall and inner liner
- Cords or steel belts are showing, or the tread is down to the wear bars
- There is a bulge, a deep cut or cracking in the sidewall
- The rubber has aged and dried out, even with good tread left
ST tires, LT tires and why the letters matter
The letters before the tire size on the sidewall say what the tire was built for. ST means Special Trailer. These tires have stiffer sidewalls that resist the side-to-side sway a trailer puts on them, and they are rated to carry trailer loads. LT means Light Truck. LT tires are designed around a truck’s steering and drive demands and are fitted to some heavier trailers, but their load capacity differs from an ST tire of the same size, so the numbers get checked before one goes on. P means Passenger, and passenger-car tires don’t belong on a trailer.
Brad matches the replacement to what the trailer needs, not just to whatever was on it last. The trailer’s tire and loading label, usually on the front half of the left side, lists the original tire size and cold inflation pressure. The sidewall of every tire lists its maximum load and the pressure needed to carry it.
Load range
Load range is the letter that tells you how much weight a tire can carry at its maximum inflation. On trailer tires you’ll commonly see C, D and E, each step rated for more load at a higher pressure. The letters replaced the old ply ratings: load range C corresponds to a 6-ply rating, D to 8-ply and E to 10-ply.
Add up the maximum load of every tire on the trailer, and the total should meet or exceed what the axles are rated to carry. Dropping a load range to save money is how tires overheat and let go on the highway.
Wheels and rims
Plenty of tire jobs turn into wheel jobs. A pothole-bent rim shakes the trailer and can leak at the bead. Cracks around the lug holes, lug holes stretched oval from running with loose nuts, and heavy corrosion at the bead seat all mean the wheel is done. One work trailer owner had Brad replace both the tires and the rims in the same job, which is often the sensible call when the rims are rusted or mismatched.
A replacement wheel has to match:
- Bolt pattern. Common trailer patterns include 5 on 4.5 inches, 5 on 4.75, 6 on 5.5 and 8 on 6.5, and they aren’t interchangeable.
- Center bore. The hole in the middle has to fit over the hub.
- Offset. Too far out and the tire rubs the fender. Too far in and it can hit the springs or frame.
- Load rating. Stamped on the wheel, and it has to carry the tire’s full rated load.
- Lug nuts. Aluminum wheels often need different lug nuts than steel wheels, so the nuts are matched to the wheel.
With a wheel off, it’s the right moment to look at the hub. A bearing that feels rough or loose goes on the list for trailer wheel bearing service.
Lug nut torque and the re-check
Trailer lug nuts get tightened with a torque wrench in a star pattern, in stages, to the value specified for the wheel and stud size. An impact gun alone either leaves them loose or overtightens and stretches the studs.
New wheels and freshly mounted tires settle as they run, so the torque drops. A common axle manufacturer guideline is to re-check the lug nuts after the first 10, 25 and 50 miles. Brad will tell you when to check and what torque to use. Skipping it is how wheels come off.
When the tire is only the symptom
Wear on one edge means something upstream is wrong, such as a bent axle or a leaf spring that has slid on its seat. Those checks live on the trailer wheel, tire and alignment page, and a bent axle is handled under trailer axle repair and replacement.
Mobile trailer tire service
A trailer on a flat is hard to move and shouldn’t be towed far. Tire service comes to you through our on-site and roadside trailer repair, at homes, yards, job sites and safe pull-offs across Morris County and the other three counties. Before he leaves, Brad checks the pressure on every tire, including the spare.
Price depends on tire size and load range, whether rims also need replacing, how many tires are involved, and how far Brad has to travel. He quotes it before any lug nut comes off. Request trailer tire service online or phone Brad any day from 7 AM until 7 PM.
Common questions
Can you fix a trailer tire on the side of the road?
Usually, as long as the spot is safe. A trailer tire can be swapped for a spare or a new tire at a roadside pull-off, a parking lot or anywhere the trailer sits on firm, level ground away from traffic. A permanent puncture repair needs the tire off the rim, so it may be done on the spot or the damaged tire replaced. Pull as far off the road as you can, and never jack a trailer on a soft shoulder.
Why do trailer tires wear out so fast?
Heavy loads, age and alignment. Trailer tires often run near their load limit, and underinflation builds heat that wears them quickly. On tandem axles, the tires scrub sideways through every tight turn. Many trailers sit for months, so the rubber dries and cracks before the tread is gone. A bent axle or a shifted spring makes one edge wear fast. Keeping pressure at the label or sidewall spec and checking alignment adds real life to a set of tires.
Should I replace trailer tires in pairs?
At minimum, replace them in pairs on the same axle. Tires side by side need to match in size, type, load range and wear so they share the load evenly and the trailer tracks straight. On a tandem trailer, all four should ideally match, because a taller tire carries more than its share of the weight. When one tire fails on a set of old tires, it is usually time to replace the whole set rather than mix new with worn.