How To Change A Trailer Tire

By Dan Armitage

When rubber meets the road, and the road wins, the result is a flat tire. Here's an 8-Step, Flat-Tire Fix-it.

Whether caused by under-inflation — the leading cause of tire failure — or physical damage from running over curbs or road debris, a flat tire on a boat trailer should be regarded as serious as a tire failure on the tow vehicle and addressed immediately. While it's true that towing a boat with a tandem-axle trailer buys you some time to drive your rig a short distance to a suitable place to fix the flat, the tire and rim can suffer additional damage with each revolution and should be repaired ASAP.

Eight Steps To Follow:

1. If you suspect a flat, immediately pull the trailer well off the road onto a level shoulder or area offering an even, hard-topped surface, and park the rig with the emergency brake engaged. Check if the flattened tire allows the jack enough clearance to fit under the frame. If not, place a piece of wood or other solid object (the spare tire/wheel will do in a pinch) in front of the flat tire. Then carefully drive the tow vehicle slowly forward so the trailer tire rolls up atop the brace and is high enough to get the jack into position. Put the vehicle back in park with the emergency brake on.

Photo of using a wrench to loosen lug nutsMake sure you carry a wrench sized to fit the trailer wheel's lug nuts.

2. Using the proper size wrench, break the lug nuts free on the wheel of the failed tire. Doing so before you raise the trailer with the jack keeps the wheel from spinning as you loosen the lug nuts.

3. When the nuts are loose, place the jack under the trailer frame on the back side of the damaged tire.

Photo of jacking up the trailerSome boaters carry a separate jack for the trailer, albeit not often a full-sized floor jack. Scissor or bottle jacks rated for the rig's weight work fine.

4. Jack up the trailer until the wheel can be taken off the lug bolts, allowing enough clearance to put a fully inflated tire back on, and remove the lug nuts and failed tire from the lug bolts.

Photo of replacing the lug nutsYou only need to jack up the trailer enough to remove the flat tire and fit a fully-inflated one on.

5. Place the spare tire on the lug bolts, replace, and hand-tighten the lug nuts.

Photo of releasing jack slowlyAfter replacing the tire, slowly release the jack to drop the trailer to the ground.

6. Release the jack slowly to drop the trailer back down until the tire contacts the road surface, allowing you to tighten the nuts with the lug wrench without the wheel spinning. Tighten the lug nuts in an alternating pattern to assure that each gets fully seated. On a four-lug wheel, tighten the nuts in a 1-3-2-4 pattern; on a five-lug wheel tighten in a 1-3-5-2-4 sequence. Repeat the torqueing order until all the lug nuts are tight to the wheel, and the wheel is tight to the hub.

7. Release the jack, allowing the tire to support its side of the trailer. Then check each lug nut again for tightness before removing the jack.

8. Get the flat tire repaired or replaced as soon as possible, mount it as a spare, or put back into position as a primary tire. 

— Published: Spring 2014


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