DRIVING/TOWING - RECOVERY TECHNIQUES
One day you’ll need to change a wheel and we show you some tricks that make the job less arduous.
One day you’re going to have to jack up your 4WD. In an ideal situation – on your level, concrete driveway – that’s straightforward, but on the roadside or in the bush, it’s far from an easy operation.
Globally every year, thousands of people die, or are seriously injured, when jacking up vehicles. Clearly, it’s a potentially dangerous procedure.
For those of us who travel in the backblocks, it’s only a matter of time before we have to jack up, so best be prepared.
Firstly, it’s important to distinguish between jacking up to change a flat tyre and jacking up to extricate a bogged vehicle. The latter operation is extremely dangerous and requires hands-on training. It’s best done with air jacks or hi-lift jacks and is not covered in this article.
(We’ve had training in how to use two hi-lift jacks in unison to de-bog a Camel Trophy competition 4WD, so we know how difficult and dangerous the procedure can be.)
At OTA we’re critical of the cavalier attitude most vehicle makers have about jacking up their products – particularly SUVs. Those that don’t supply a spare wheel don’t expect you’ll ever have to do the job!
Most of the scissor-jack jacking points are bodywork locations, in the side rocker panels. After-market side-steps sometimes block access to these points.
The worst 4WD jacking points are at the rear ends of wagons and utes that have over-slung leaf springs or coils. If you position the jack under the rounded section of the axle, relying on the shallow depression in the head of the jack shaft to locate it, the contact area is small and offers no positive location. We know from experience that’s asking for trouble.
A slip-on adaptor – usually a U-shaped bracket – for the head of the jack shaft is vital, we feel, so if your jack doesn’t have one, buy one or get one made.
There are some proprietary adaptors around, but they’re quite general in shape and you may need a custom-built one. One of our OTA Supporters made his own, which he assures us is sufficiently strong: it looks it!
Another possible complication occurs if your 4WD has been lifted and runs on large-diameter rubber: the standard jack may not have sufficient ‘stroke’ to lift a flat tyre clear of the ground.
It’s important to practise wheel changing at home, so you know the jack limitations.
After-market jack shaft extensions are part of US-market jacking kits, but if you find you need a long extension you’d be better off with a larger-capacity-longer-stroke hydraulic jack.
Now, we’ll tell you how we at OTA have avoided having to jack up our 4WD for a few years.
Avoiding having to change tyres
We have six wheels, shod with six tyres that we rotate to even out tread wear. We don’t jack up the 75 Series to do that; we time it for a vehicle service and the workshop boys do it while it’s on their hoist.
Once our tyres are half-worn we don’t use them on stony roads: we sell them or trade them in and buy new tyres. That way, we minimise through-tread punctures that occur much more easily on worn tyres.
We use tyre pressure monitoring, to ensure that our tyres always operate at the right pressures for load and speed conditions.
If we do get a puncture the TPMS warns us instantly and we can pull up before the deflating tyre is damaged. If we’re on a bush track we can often insert a temporary tyre plug into the hole and continue our trip without having to jack up and put on a spare.
However, we always carry the following equipment: two jacks (one hydraulic and one mechanical); a 25mm-thick compressed-plywood, load-rated jacking plate; a tyre air compressor; a back-up foot air pump; spare valves; a proper tyre plug repair kit with a reamer and a Ufixit wheel nut spanner for tight wheel nuts. So, we’re well set up for jacking if we have to.
Safe jacking on-road
Infrequently, we have to demount a wheel and tyre, because a ‘plugged’ tyre isn’t safe for road use unless it’s been inspected by a specialist. If we’ve plugged a tyre in the bush, we change it for a good tyre before heading on-road.
Also, we test many new 4WDs and they usually don’t have bush-friendly LT tyres, so they’re more likely to get punctured.
When we do have to change a wheel and tyre, we select a firm level surface, away from traffic hazards.
If we’re unlucky enough to have to do the job on the side of a road or track, safety is the primary concern. Jacking on a slope is a big no-no and can never, ever be a safe procedure.
If the tyre still has some pressure in it, the vehicle can be driven a short distance at low speed, to a safe, level spot.
If the tyre is dead flat and won’t hold enough temporary air to lift the sidewalls off the ground, it’s probably never going to be safely used again, so manoeuvring the vehicle on it and crushing the sidewalls won’t matter.
Once in a safe, level spot it’s time to start jacking up. Firstly, ‘though, put the vehicle in 4WD-locked mode, in first gear or Park and apply the handbrake.
Get all the equipment you’ll need – especially the spare wheel – out of the vehicle and don’t let anyone go near the vehicle until the entire wheel changing process is finished.
People wrestling with spare wheels, boarding vehicles, or opening and slamming doors or boot lids is a common cause of vehicles falling off jacks!
If the jack won’t fit in the vertical space between the jacking point and the ground plate you may have to increase ground clearance by putting some air into the flat tyre, or driving the flat tyre onto a rock or piece of timber.
Put the spare wheel flat on the ground, near the wheel you’ll be jacking up and ‘break’ the wheel nut tension. Doing that before you jack up the vehicle means you’re not putting too much twisting action into the jacked-up wheel end.
Use chocks – rocks or timber – in front of and behind all three tyres that won’t be raised on the jack.
Put the jack ground plate in place, under the nominated jacking point, even if the ground looks firm and smooth.
Position the jack carefully and slowly in position under the vehicle manufacturer’s suggested jacking point. Note that if that’s a bodywork point the jacking height will need to be much greater than if it’s under an axle or suspension component, because the wheel won’t lift off the ground until suspension ‘droop’ takes up.
Our 75 Series is relatively easy to jack up safely, because it has leaf springs mounted under the front and rear axles, which means there are large U-bolt pads at each wheel end. It’s easy to locate a jack under these points.
Even so, we use two jacks, not one – just in case. Having a second jack also covers the situation where a jack jams in place. You can use the second jack to free the first.
As you operate the jack handle and the vehicle starts to rise, slide the spare wheel and tyre partly under it, as a safety stop in case the jack does slip.
While operating the jack, observe what’s happening and be ready to stop and restart the process if the jack or the jacking plate gets out of shape.
Raise the wheel until there’s just sufficient clearance to position the spare in place. Then undo the wheel nuts carefully, without causing the vehicle to wobble on the jack. Put the nuts in a safe place, so they can’t roll away or get grit in the threads.
To get the wheel off the hub, put a shovel blade, jack handle or wheel brace under the tyre and lift this lever so that the wheel centre and stud holes can clear the hub. Tilt the top of the wheel towards you and when it’s clear roll it to one side.
Pull the spare out from under the vehicle and put the flat tyre in its place.
To fit the spare wheel, roll it in place in front of the hub, with holes lined up with the stud positions. Wriggle the bottom edge inwards, stand the wheel vertically and check that the stud holes are still lined up.
Poke the end of your lever under the bottom of the tyre and lift the free end of the lever to raise the wheel and tyre into position on the hub and studs.
Spin on the topmost nut and it’ll hold the wheel upright while you spin on the other nuts. Tighten them gently with your spanner, but only to seat the wheel on the hub. Don’t apply enough force to move the vehicle on the jack.
Now, slide the flat tyre and wheel out from under the vehicle and slowly lower the jack. When the tyre is contacting the ground enough so that it won’t rotate, tighten the wheel studs in a staggered pattern. Then completely lower the jack.
Pull the jack and jacking plate out from under the vehicle and check the pressure in the newly-fitted tyre. Fit the TPMS sensor cap.
After driving for a few kilometres, stop and check the wheel nut tension. Then check tension again after a few hundred kilometres.
The jack that comes with your 4WD has only one purpose: to raise the vehicle temporarily, while a wheel is changed. It’s safe, if used in accordance with instructions.
All jacks sold in Australia, including those that come with new vehicles, are required by law to comply with Australian Standard AS/NZS 2693.
Trolley jacks or floor jacks are required to comply with another standard, AS/NZS 2615.
Both specify the requirements for the design, construction, performance and labelling of jacks and are your guarantee that the product meets the required safety standards.
Jacks of any sort are not intended to support vehicles while they are being worked on: that’s what safety stands are for. Safety stands are covered by AS/NZS 2538.
Some after-market bottle jacks integrate an axle stand with the jack and the stand is locked in the raised position by inserting a pin into the stand shaft.
The following are a few basic jack safety precautions: use a jack only on a hard level surface; do not exceed the jack’s specified lifting capacity; jack only under the designated lifting areas to ensure the vehicle is not damaged and that the jack will not slip; wedge chocks under the vehicle’s tyres that remain on the ground, so that the vehicle cannot roll while being lifted.
Some people advocate using a trolley or floor jack, rather than a bottle or scissor jack. The relative strength and stability of a four-point floor jack is attractive. However, a trolley jack’s wheels need to roll as the vehicle is raised, because the lifting ram works in an arc, not directly vertically.
If the small-diameter wheels can’t roll, because the ground is uneven, soft or rocky, the vehicle may slip off the jack.
Exhaust gas lifting bags or air bags are viable alternatives to metal jacks, but they need to be protected from damage by sticks and stones, or by sharp metal components under the vehicle.
A mechanical or hydraulic high-lift jack is another alternative, but if you haven’t received practical training in using one, don’t even think about it. Also, many modern vehicles aren’t compatible with high-lift jacks and panel damage, or worse, can result.
Never crawl under a vehicle that is supported only by a jack. Before going underneath, place jack stands under appropriate parts of the vehicle and lower the vehicle onto the stands. Make sure that the vehicle is securely settled before going underneath.
Use safety stands to support a vehicle. Do not use bricks, concrete blocks or wood.
Spare wheel handling
A ‘real 4WD’ wheel and tyre can be a fairly heavy combination: between 30kg and 45kg and you don’t want to risk back damage man-handling or woman-handling one more than you need to.
The most common spare wheel location is under the rear of a 4WD’s cargo space, where it’s relatively easy to raise and lower it, using the winch handle provided.
Alternative locations are inside a wagon, or on the tray of a ute and the following video shows you how to use a shovel as a ramp to roll it up and down, without much risk of back injury.
Don’t forget to stow the removed wheel and tyre in its designated position. Here’s a video of how we stow ours: