A jockey wheel that won't wind, wobbles under load, or has a flat-spotted tyre isn't just annoying — it's a hitch-up hazard. The good news: swapping a trailer jockey wheel (tongue jack) is a job most owners can do in under an hour with basic hand tools. This guide walks through the whole process, from sizing your replacement to torquing the final bolt.
When to replace your jockey wheel
Replace the unit rather than nurse it along if you notice any of the following: the wind mechanism grinds or slips, the inner tube leaks or the tyre has gone hard and cracked, the barrel is bent from an off-road knock, or corrosion has seized the height adjustment. On trailers that see gravel, sand, and water crossings, a sealed-bearing off-road jack is worth the upgrade — open bushings pack with grit and fail fast.
Tools and parts you'll need
Grab a socket set or spanners, a flat-head screwdriver, penetrating oil, a wire brush, and a torque wrench. You'll also want a replacement jack matched to your trailer's weight and clamp diameter. Most Australian-style off-road couplings and drawbars use a 48 mm barrel, which the ARK XO range fits directly.
Sizing your replacement jack
Two numbers matter: clamp diameter (so the new jack slides into your existing bracket) and static load rating (so it carries your loaded tongue weight with margin). Use the table below as a starting point.
| Trailer type | Recommended ARK jack | Static rating | Max height |
|---|---|---|---|
| Teardrop / small utility | ARK XO350 | 770 lb | 3 heights to 21" |
| Mid-size off-road camper | ARK XO500 / XO500 Black Edition | ~1,100 lb | 4 heights to 28" |
| Tandem-axle / fully loaded caravan | ARK XO750 | 1,650 lb | 4 heights to 28" |
If you're between sizes, size up — a jack rated well above your tongue weight winds easier and lasts longer. The ARK XO500 is the sweet spot for most mid-size off-road rigs, while heavier tandem-axle trailers should step up to the ARK XO750.
Step-by-step replacement
1. Stabilise the trailer. Chock the wheels and, ideally, support the drawbar on a jack stand so nothing drops when you loosen the clamp.
2. Wind the old jack up. Retract the leg fully so the wheel clears the ground, making the unit easier to handle once free.
3. Loosen the clamp bolt. Back off the swivel-clamp nut on the mounting bracket. Hit stubborn threads with penetrating oil and give it a few minutes.
4. Slide the old unit out. Lift the jack straight up and out of the clamp. If it's seized in the bracket, wire-brush the barrel and work it free — avoid levering against the bracket casting.
5. Clean the bracket. Wire-brush rust and old grease from the clamp bore so the new barrel seats square. A smear of anti-seize on the barrel makes future service easier.
6. Fit the new jack. Slide the new barrel into the clamp, set your ride height so the wheel clears obstacles when travelling, and orient the wind handle where you can reach it.
7. Torque the clamp. Tighten the clamp bolt firmly so the jack can't rotate or slip under load, but don't over-crush the barrel. Check your bracket's spec if you have it.
8. Test. Wind the jack down until it takes the tongue weight, then back up. It should raise and lower smoothly with no wobble, and the wheel should roll freely when you reposition the trailer by hand.
Fit it and forget it
Once the new jack is on, a minute of care keeps it rolling: rinse road salt and mud off after trips, keep the height-pin holes clean, and store a removable side-wind handle inside so it can't rattle loose. Sealed-bearing designs like the XO range need far less babysitting than open-bushing jacks, and ARK's units are salt-spray tested to 600 hours to resist the corrosion that kills cheaper wheels. Not sure which model suits your trailer? Compare the full lineup in the ARK off-road trailer jack collection.
Ready to upgrade? Every ARK XO jack ships fast from our warehouse in Upland, CA, and they're the same off-road jacks fitted as OEM equipment on Black Series campers — so you're bolting on exactly what the factory trusts.