How do you store a trailer so it tows well next season?

Four things, and none of them are mileage related. Ultraviolet light and ozone break down tire rubber continuously, whether the trailer moves or not, which is why an ST tire is widely recommended for replacement at 5 to 6 years from its manufacture date regardless of how much tread is left. A lead acid battery, including the small one behind a breakaway switch, self-discharges over weeks even with nothing connected to it, and a deeply discharged battery loses capacity permanently rather than simply needing a recharge. A trailer left resting on its tongue jack for months puts a sustained, unchanging load on a hydraulic seal that was built for repeated short lifts, not for holding weight indefinitely. And wheel bearing grease that sits still in a hub for a long stretch can allow moisture that condensed inside the hub to settle rather than staying mixed through, which is exactly the setup for corrosion on the bearing races.

None of these four things announce themselves. A tire that has quietly aged past its service life looks the same as a new one until the sidewall cracks or separates at speed. A breakaway battery that died in storage gives no warning until the one moment it is actually needed, which is the trailer separating from the tow vehicle. Storage habits exist specifically to catch problems that have no earlier symptom.

This is widely taught towing convention rather than a single published standard, because the right interval depends on climate, storage location and how long the trailer actually sits. Use it as the baseline and adjust for a genuinely long, cold or sun-exposed storage spot.

An ST trailer tire spends most of its life parked, and rubber does not need mileage to degrade. Ultraviolet light and ozone break down the compounds in the sidewall continuously, which is why the widely published guidance is to replace an ST tire at 5 to 6 years from its manufacture date regardless of remaining tread depth, read from the DOT date code on the sidewall. A trailer stored outside without any tire protection for years at a time is spending down that 5 to 6 year clock every single day it sits in the sun, tread wear or no tread wear.

A set of four tire covers sized for 26 to 28.75 inch wheels handles most tandem axle travel trailers, and the smaller 23 to 25.75 inch set covers most 14 and 15 inch trailer wheels. Either one is inexpensive relative to what a set of trailer tires costs, and it is one of the few items on this page that visibly pays for itself: a tire that has spent its life under a cover looks noticeably less sun-checked at the same age than one that has not.

A breakaway switch does nothing on its own. It is a mechanical lever wired to a small battery, and that battery is what actually pulls the trailer brakes on if the trailer separates from the tow vehicle. The normal condition of a trailer that has sat for a season with no maintenance is a breakaway battery that has quietly discharged past the point of holding a useful charge, and the switch, the cable and every other part of the system can be in perfect condition while the one component that actually matters is dead.

A breakaway kit with a built-in charger and an LED state of charge display solves the part of this problem nobody can see otherwise: it shows whether the battery is actually charged rather than leaving that as a guess. Left plugged in through the storage period, or checked and topped off monthly if it cannot stay connected to power, it is the single cheapest insurance on this entire list against the one failure mode that matters most.

Wheel bearing grease is not just lubrication, it is also what keeps moisture away from the bearing races. A hub that sits still for months with grease that has already picked up condensation from the last trip gives that moisture time to settle rather than staying mixed through the grease, and settled moisture against a bearing race is exactly how corrosion starts on a part that otherwise never wears out on its own schedule. Packing fresh grease into the hub before a long storage period displaces the old, potentially contaminated grease with clean grease and buys the bearing genuine protection for the months ahead.

A tub of trailer bearing grease or a cartridge sized for a standard grease gun both work for this job; the cartridge is the more convenient format if a grease gun is already in the toolbox. See how to repack trailer wheel bearings for the full procedure, and do it again before the first loaded trip of the new season rather than assuming the pre-storage grease job is still good after months of sitting.

A tongue jack is built to lift and lower a trailer repeatedly, in relatively short cycles. Leaving a trailer's full tongue weight resting on that jack's hydraulic seal continuously for a season is a different kind of load than the jack was designed around, and a seal that holds under normal cycling can weep or fail under sustained static pressure over months. The fix costs nothing: lower the jack until the trailer's weight is carried by the ground through blocks or the axle, chock the wheels so the trailer cannot roll, and let the jack sit unloaded or nearly unloaded through the storage period.

A basic pair of wheel chocks covers a single axle utility trailer, and a locking tandem axle chock does the additional job of removing the fore-and-aft rock a tandem axle trailer develops when nothing is holding the two tires against each other. Either one, placed correctly before the jack takes any weight off, is what actually protects the jack rather than the storage duration itself.

Everything done at storage time gets checked again before the first trip, not assumed to still be good. Recheck every tire's cold pressure against the sidewall maximum rather than trusting the number it held when it was parked, confirm the breakaway battery actually holds a charge under load rather than just showing a light, test the trailer brakes and the breakaway switch itself, and inspect the bearings if the trailer sat for more than a few months. The first trip towing checklist covers this wake-up sequence in full, and it is worth treating the first trip after any long storage period the same way as a genuinely first trip, since a season of sitting can quietly undo work that was done correctly months earlier.