Changing a tire
Always carry a full sized spare tire when you hit the trails.
Sometimes we have no choice but to change out a badly damaged tire with the spare. On a level surface, with a floor jack – a tire change is not too difficult. But on the uneven, slippery terrain of a dirt trail, without the convenience of garage equipment – the process becomes challenging, especially if you are traveling without a group.
However, I have watched tire changes take place on trails with the speed and precision of a NASCAR pit crew. There is strength (literally) in numbers. Yes, those big tires are heavy. Lug nuts can be stubborn. Someone who is agile needs to slip under the vehicle to position the jacks. Maybe a battery powered impact driver appears in somebody’s hands… and several minutes later the whole deed is done!
The first step in changing your tire is to find a flat and level place to stop.
The ground needs to be firm and solid; you don’t want the vehicle or jacks to slip. Grab some rocks and chock the tires.
Remove the spare tire and loosen the lug nuts of the damaged tire. Personally, I don’t use locking lug nuts, in case the adapter key socket gets misplaced or lost; or in case a lug nut binds (some of the locking nuts do not afford as solid a grip).
The best way to raise up a Jeep is to place the jack under the axle or differential cover.
Trying to jack up a lifted Jeep from the side rail or chassis is difficult, since the axle is suspended under the body and will not rise until all of the slack in the lift stretches out. That can be an awful lot of elevating – sometimes even greater than the height of a hi-lift tractor jack!
Sometimes, there isn’t enough clearance to slide a bottle jack under the axle. It may be necessary to inflate the damaged tire in order to gain an inch or so.
If there still isn’t enough space, sometimes adding traction boards or some large and stable rocks under the flat tire will bring that side of the axle up a bit. Do not use rocks under the other three tires, because you will compromise stability.
Another trick is to use the original scissors jack to raise up the axle just enough to get the bottle jack in place.
Let’s discuss jacks.
Hi Lift or Tractor/Farm Jack
Hi-lift jacks (aka tractor or farm jacks) definitely look cool when mounted on your mall crawler, but they have limited usefulness.
Hi-lifts can be very unstable and tip easily. For some recoveries, we tip them over on purpose in order to elevate and laterally shift a tire placement, such as when a tire is dangling over a precipice so that it cannot just be winched sideways.
That long metal bar that serves as a lever can slip, and fling wildly upward. You never want to lean over it with your body or have your head in its path. Always have a spotter watching the person operating the jack, because it is easy to forget about body position.
Hi-lifts require a very solid mounting point on the vehicle. Steel bumpers or reinforced side rails. Plastic bumpers and flimsy running boards will not support the weight of your vehicle. I would guess that 60% of the Jeeps adorned with mounted hi-lifts are not equipped with suitable mounting points, thus rendering those jacks useless.
“There are a lot of good applications for using hi-lifts, but tire changing isn’t really one of them.”
Bottle jacks (aka hydraulic) are the preferred tool, unless some enthusiast actually brings a floor jack along in the back of their truck. Basic bottle jacks are compact and lightweight. However, the lifting piston is small and resembles the bottleneck of a beer or soda.
Unijack
To improve the grasp, there is an accessory known as a “bottle jack buddy” that sits over the narrow piston and provides a saddle for the axle.
Another style of bottle jack is the unijack or powerjack. This design combines the larger base and lock of a jackstand with the lift of a hydraulic or bottle jack and feature a built-in saddle. They take up a little more room in your recovery bin, but all of that extra stability is worth it.
Once the axle is raised enough for the damaged tire to clear, finish unscrewing the now loosened lug nuts. Change out the tires. If the new tire is just a tad too tall to mate with the lugs, try deflating it.
Tighten the lug nuts somewhat (don’t torque them yet). Lower the jacks and remove them. With the new tire on the ground, go ahead and really tighten them down. Tighten the lugs in a star pattern, and go around a second time.
Check tire pressure so that the new tire matches your (offroad) psi.
