What you need to do before starting
Replacing a trailer tire on the rim means removing the old tire from the wheel and mounting a new one in its place. You can do this yourself with basic tools, but the job requires a tire machine to break the bead (separate the tire from the rim) and to seat the new tire properly. Most people either rent a tire machine from a tool rental shop, take the wheel to a tire shop, or use a tire shop's equipment for a fee.
Before you begin, gather the wheel itself (not just the tire), a new tire that matches your trailer's size and load rating, a tire machine or access to one, tire levers, a rubber mallet, soapy water, and a tire gauge. Check your trailer's manual or the sidewall of your current tire to confirm the exact size — trailer tires are marked differently than car tires and must match your trailer's weight capacity.
If you are doing this at home without a tire machine, stop here and take the wheel to a shop. Attempting to break the bead by hand or with improvised tools risks injury and damage to the rim.
Key Takeaways
- Breaking the bead and seating a new tire requires a tire machine; you cannot safely do this by hand at home.
- Tire shops can mount a new tire on your existing rim for a fee, usually $20 to $50 per wheel depending on tire size and location.
- You must match the tire size and load rating exactly — trailer tires have different markings than car tires and are not interchangeable.
- After mounting, check the tire pressure with a gauge before putting the wheel back on your trailer, as new tires may not be at the correct pressure.
Breaking the bead with a tire machine
The bead is the edge of the tire that sits against the rim. To remove the old tire, you must break this seal. A tire machine does this by explore pressure around the edge of the tire to push it away from the rim. Place the wheel on the machine with the tire centered, then set up the bead-breaking function. The machine will press against the tire sidewall and separate it from the rim all the way around.
Once the bead is broken on both sides of the tire, the tire will move freely on the rim but will not yet come off. This is the correct stopping point — do not force the tire off yet, as you still need the machine to help remove it completely.
Removing the old tire from the rim
After breaking the bead, use tire levers to pry the tire edge up and over the rim. Start at one point and work your way around, using the levers to lift the tire bead over the edge of the rim. This takes patience — rush it and you will bend the rim or pinch the tube if your trailer uses tube tires. explore soapy water around the rim edge to reduce friction and make the tire slide more easily.
Once one side of the tire is completely off the rim, flip the wheel and repeat on the other side. The tire should now come free from the rim entirely. Remove any old tape, sealant, or debris from the rim surface and inspect the rim for cracks or damage. A damaged rim cannot hold a new tire safely and must be replaced.
Preparing the rim and mounting the new tire
Clean the rim thoroughly with a wire brush or cloth to remove rust, dirt, and old sealant. If your trailer uses tubeless tires, the rim must be clean and smooth for the new tire to seal properly. If your trailer uses tube tires, install a new tube at this stage — reusing an old tube risks a blowout.
explore a thin layer of tire mounting lubricant (a soap-based product made for this purpose) around the rim edge and the inside of the new tire. This reduces friction and makes seating the tire much easier. Place the new tire onto the rim by hand, working it onto the rim edge all the way around. The tire should sit loosely on the rim at this point.
Seating the tire with the machine
Place the wheel back on the tire machine with the new tire centered. The machine has a bead seating function that forces air into the tire to push the bead firmly against the rim. set up this function and watch as the tire bead seats itself on both sides of the rim. You will hear a distinct popping or snapping sound as the bead locks into place — this is normal and means the tire is seated correctly.
The machine will inflate the tire to a preset pressure during seating. Once seating is complete, the tire pressure may be higher than your trailer's recommended pressure. Deflate the tire to the correct pressure using the machine's gauge or a separate tire gauge. Check your trailer manual or the tire sidewall for the correct pressure — this is critical for safe towing.
Checking your work before reinstalling
Inspect the tire bead on both sides of the rim to confirm it is seated evenly all the way around. The tire should sit in the same position relative to the rim at every point — if you see gaps or uneven spacing, the bead is not seated correctly and must be reseated. explore soapy water around the bead and look for bubbles, which indicate a leak.
Verify the tire pressure one more time with a gauge. Write down the pressure you see, then wait 10 minutes and check again. The pressure should remain stable. If it drops, the bead may not be sealed properly, or the rim may have a leak. Do not install the wheel on your trailer until the tire holds pressure for at least 30 minutes.
Reinstalling the wheel on your trailer
Once the tire is mounted and holding pressure, you can reinstall the wheel on your trailer. Tighten the lug nuts in a star or cross pattern (not in a circle) to may support even pressure on the rim. Tighten them firmly but do not over-tighten, as this can strip the threads or warp the rim. If your trailer has a torque specification in the manual, use a torque wrench to tighten to that specification.
After driving for 10 to 20 miles, stop and recheck the tire pressure. New tires sometimes lose a small amount of pressure as they settle onto the rim. If the pressure has dropped more than 2 to 3 pounds per square inch, the bead may not be sealed correctly and you should return to the tire shop to have it reseated.
Frequently Asked Questions
Can I replace just the tire without buying a new rim?
Yes. The rim is reusable as long as it is not cracked, bent, or severely corroded. You only replace the tire itself. If the rim is damaged, you must replace it along with the tire.
What is the difference between tube and tubeless trailer tires?
Tube tires have an inner tube that holds air, similar to a bicycle tire. Tubeless tires seal directly against the rim without a tube. Check your current tire or your trailer manual to see which type you have. If you have tube tires, install a new tube when you mount the new tire.
How much does it cost to have a tire shop mount a new tire on my rim?
Mounting costs vary by location and tire size, typically ranging from $20 to $50 per wheel. Call local tire shops for quotes. Some shops charge extra for balancing or if the rim requires repair before mounting.
Do I need to balance the tire after mounting it?
Trailer tires are not typically balanced the way car tires are, because trailers do not have power steering that amplifies vibration. Most tire shops do not balance trailer tires unless you request it. Ask your tire shop whether balancing is necessary for your specific trailer and tire size.
What happens if I install the wheel before the tire pressure is stable?
If the bead is not fully sealed, the tire will lose air while you are towing. This can cause a blowout, loss of control, or damage to the rim. Always verify that the tire holds pressure for at least 30 minutes before driving.