UP ‘N’ AT ‘EM
Words by Pat Callinan and Photography by ARB and Pat Callinan
Tackling steep hills is fun, if you know how
I still remember that first feeling of looking at blue sky and nothing else through the windscreen. "Oh sheet" I think were the words racing through my head, as my fingers tightened around the wheel.
That great sensation of tackling steep terrain never really leaves you, but you do get more used to it. You learn to trust your fourby because, after all, they’re built for this terrain. Low-range gears give 4WDs the ability to tackle seemingly impossible inclines without stalling, but the ever-present issue of traction is always the great leveller.
This is why, for most vehicles, low-range second is the ideal gear to tackle the steep stuff. Think about it, if you try to run up a steep hill it’s nice to have a little momentum. Well, it’s no different with a fourby, only this time you’re hauling about 2t. Second gear is slow enough to maintain control and quick enough to maintain momentum. First gear can cause the fourby to labour, which translates to wheelspin, because there’s too much power and not enough inertia.
However, you can’t really apply the old ‘second gear, low range’ rule to all vehicles. My old 2.25L Series 2A Landy diesel had less puff than a poofter after Mardi Gras, so first gear low-range was the only option. Likewise, you might find that the gearing on your 4WD is simply too high and in second gear it’s just too fast, or you’re stalling all the time. Do what is comfortable for your vehicle.
If you have an auto transmission, you’re lucky. Just select low-range and ‘D’ for Drive and let your fourby do the rest. All you need to do is monitor the speed and traction, and the torque converter will sort you out. The only exception here is when you are travelling up an extremely long hill (like a few kays), and your auto-box keeps on hunting for gears and can’t seem to find the right one. If that is the case, lock it into first or second gear.
Too much gear hunting can cause the transmission-fluid temperature to rise. If you have a camper-trailer on the back, you could be placing your tranny under too much stress. If it does overheat, there aren’t too many trackside repairs that I know of for an automatic. So, just park your truck, let it cool down and try again. If it keeps happening, consider having a transmission cooler fitted (or a bigger one if your vehicle already has one).
So you have the gears sorted, but what should you do at the bottom of the hill? Get out of your comfy seat, and have a damn good look at what you’re up against. If you’re in a convoy, don’t be embarrassed about doing this. Better to understand what you’re tackling, than get caught in a nasty situation halfway up and have to make a dangerous recovery.
Obviously you’re not going to walk the whole hill, otherwise this would be a bushwalking magazine, not a fourby mag. Have a look for potential obstacles, areas where you can stop for a breather (like whoop-de-doos), or parts of the track that need to be built-up. This can save you a lot of trouble. You might even decide that the hill is beyond you or your truck’s ability and leave it for a later trip. Either way, you’re in front.
 |
Now that you have assessed the hill and determined it’s good to drive, lower your tyre pressures. You want maximum traction and the only way to get that, is to increase the footprint of your tyre on the track. Without beadlocks, don’t dump your pressures much lower than 15 psi, with beadlocks, go nuts. I’ve been known to dump the valves out of my Zook on certain hills, and the traction is awesome. Just remember to re-inflate when you get to the top of the mountain.
One last thing before you attempt the incline. Engage your traction aids, whether they are centre differential locks or traction-control systems. Cross-axle diff locks are great, too.
|
Personally, having manually controlled Air Lockers, I tend to leave them off until necessary, engaging the rear, then the front locker. Be careful with cross-axle diff locks though as, particularly on the front axle, they severely limit your ability to steer.
If you come across some wheel ruts halfway up the hill, what do you do? Steep terrain usually equates to steep drop-offs on the side of the track, which you want to stay on at all costs. Think of ruts as railway tracks made by drivers before you, they tend to ‘lock you in’ to the track. Out of the ruts, you’re at the whim of the side slopes and more susceptible to sliding off the side and into trouble. Of course, if a 40 Series LandCruiser running 44in Boggers has just paved those ruts before you, don’t expect that your 31in rubber will give you enough clearance to get through.
If the track looks safe enough, and you’re in no danger of sliding off the track (and the wheel ruts are just downright uncomfortable) then by all means, get your truck out of them - always being careful to stick to the main track. Let’s tread lightly, eh?
So, what happens if you make it half way up Mt Nutcracker, but you can’t make it any further? Whatever you do and however tempted you are, don’t try to turn your truck around. If there’s one thing 4WDs don’t like, it’s side slopes. You could find yourself doing a triple barrel roll with pike down the mountain, which sort of ruins a nice day out. Yep, what goes straight up, must come straight down. Only this time, backwards. Reversing down steep hills is the only way to go, but for that, you’ll need to learn how to do a ‘stall recovery’. Sounds fancy dunnit? Let’s look at manual vehicles first.
So you have stalled. Stomp on your footbrake, and leave your fourby in gear. At this stage, your clutch is your enemy, steer clear of it! Engage your handbrake. This process gives your vehicle the best chance of holding traction on the steep hill, because both the gearbox and the brakes are locking you in place.
Now it’s time to check your mirrors, look over your shoulders and try to pick a line down the hill. With your right foot still firmly planted on the brake pedal, push the clutch down gently and select reverse. If your fourby starts to slide while you’re selecting reverse, go to Plan B. This involves screaming "we’re all gonna die! Save yourselves before it’s too late!" Okay, so that’s what you will feel like doing, but the trick is to lay off the clutch, lock up your brakes and secure the vehicle with a strap or a winch to a tree. This way, if the vehicle rolls back while you’re selecting reverse, it will at least be secured.
Once you have managed to successfully select reverse gear, keep your eyes fixed firmly on your rear-view mirrors like an off-roader possessed. With your foot still planted on the brake let off your handbrake. Then, let your gearbox take up the slack, so it’s only your footbrake and the gearbox holding your truck. Not touching the clutch, turn over the engine and let your foot off the brake. Your vehicle should just idle down the hill.
In steep terrain, ignore the temptation to stomp on your brakes, and take it as slowly as possible. If your vehicle starts running away then by all means feather the brakes, but stomping on them is a bad idea. Think about it. You steer with your front axle, and most of the vehicles weight is on the rear. Hitting the anchors only transfers more weight to the downhill (back) axle, so your chances of steering properly are greatly diminished. I’ve seen many a fourby going backwards down a hill, where the front end tries to overtake the back end, because the driver was too eager to hit the brakes. Better to go faster and have steering, than slower and have none, I reckon.
So, that is manual fourby’s, what about autos? Once you’ve stopped, jump on the footbrake, and wrench on the handbrake. Now select Park. Check your mirrors, and get ready to reverse down the hill. Then start your vehicle, select reverse, and let off your handbrake, and then your footbrake before backing down. It’s slightly less effective than a manual transmission, but remember you only need to use the stall recovery technique on really steep hills where traction is compromised.
It’s a good idea to practice the steps of a stall recovery on less challenging terrain first, before having to strut your stuff when it really counts.
STEEP INCLINE BASICS
Walk the track first
Lower tyre pressures
Engage traction aids
Second gear, low range or ‘D’ for autos
Maintain momentum, but don’t speed
Never try to turn on a hill
Stall recovery
STALL RECOVERY
MANUAL TRANSMISSION
Stall the vehicle in gear by applying the footbrake
Select the park brake
Once the vehicle is secure, select reverse and then take your foot off the clutch
Let off the park brake
With your feet off the clutch and accelerator, crank the engine while letting off the footbrake
The engine will start and the vehicle will reverse down the hill.
Idle down the hill, being careful not to hit the brakes too hard
AUTO TRANSMISSION
Stall or stop the vehicle with the brake
Engage the handbrake
Select park
Turn on the vehicle
Select reverse
Disengage the handbrake and footbrake
Idle down the hill, being careful not to hit the brakes too hard
GEAR YOU NEED
Tyre-pressure gauge
Low-range lever
Ghoulies
Recovery straps and shackles
GEAR YOU WANT
Cross-axle differential locks
Aggressive tyres
Winch
Bead locks
|
|
