Off Road - Rock Climbing

[Disco]

Tire pressures should be in the range of 24-36 psi depending on the situation.

ASCENDING

Diff lock and axle lockers (if fitted) engaged.
Select low range gears only!
If air conditioning is on, turn it off.

If climbing over sizable rocks, put one front wheel or the other directly on the rock. Don’t pass over rocks by straddling them. Put the wheel squarely on the rock. Avoid too small a bite with the tyre, or the wheel may slip off to the side, tearing the sidewall on a jagged edge. Avoid “side hill” positions, with one side of the vehicle a lot lower than the other.

If the vehicle cannot continue to climb, try turning the steering wheel from side to side; do not change gears, as this will cause loss of momentum. If it stalls and continued forward travel is desired, select a lower gear; engage the hand brake and release it, as the clutch is slowly released.

If the vehicle has stalled, and forward travel looks unlikely, engage the foot brake, and then reverse gear (low range), apply the hand brake; then come off the brakes. Slowly release the hand brake and then turn on the ignition and reverse back down ‘squarely’. Keep off the brakes and clutch!

Diff lock and axle lockers can be engaged or disengaged at any speed; in any gear, without the use of the clutch, provided you are steering straight ahead.
On solid rock, be aware that the steering will be hard. If a corner or sharp bend needs to be negotiated, switch off your front lockers (if fitted), and if necessary the rear as well.
Give the throttle a ‘bump’ to assist in disengaging ‘maxi drive lockers’ (if fitted) after switching off.

HILL STALL RECOVERY

• If the hill becomes too steep, allow the vehicle to stall whilst in gear. Do not touch the clutch.
• Apply the brake & hand brake. Depress the clutch and select reverse low range.
• Take foot off the clutch, disengage the hand brake, and slowly come off the foot brake.
• Check the track behind is clear.
• Start the engine – keeping all feet off all pedals.
• The starter motor will start to drive the vehicle backwards as the engine begins to fire.
• The Hill Stall Recovery does not apply to automatic vehicles as they should not stall, just lose forward drive when the hill becomes too steep for the gear selected.

• A lesser used method where the terrain is not extremely steep and forward travel is desired, but wheel spin will result if the clutch is let out. This method only applies to manual transmissions and drive trains that have very low forward gears (crawler gears). Leave the vehicle in gear and start the engine without pressing the clutch. The vehicle will begin to move forward while the engine fires. Once the engine fires forward movement can begin. This method is hard on the starter and electrical system and should not be attempted on very steep terrain due to possible overload on the electrical system and starter.

DECENDING.
Diff lock and axle locks engaged. Select low range gears only.
If you cannot see the route exit, walk it first! Remove any badly placed rocks.
• Go over the edge as slow as possible.
• Turn ‘ON’ the air conditioner for extra engine braking.
• Keep off the clutch and use only light braking when needed.
• If the engine stalls, restart it by turning the ignition whilst in gear with the foot off the clutch.
• If towing a trailer and it begins to slide, accelerate slightly to correct.
• If your vehicle begins to slide, accelerate slightly.
• If the vehicle jumps out of gear, stop, before putting it back into gear.
• Keep thumbs outside the steering wheel spokes.
• On steep rocky descents, select neutral, hard on brakes! (winch cable may be needed)

[SCSL]

Great series of threads!

Best advice for rock-crawling is: "Take the high road"
The number one mistake I see folks make on rocks, that leads to damage, is not putting their tires up on the rocks. As Disco stated, trying to "stradle" or other wise avoid the rock. Big mistake, as the tires are designed to take the rock, not the axle, diff, etc.

Number two mistake is not airing down sufficiently. I would say that 24-36 psi is even on the high side. The tires need to conform to the rocks, rather than bounce off them. Tire selection is important, with solid side walls - they will get banged up, as will your wheels, lug nuts, etc.

Number three mistake, and it's not really a "mistake", is lack of HD sliders,, some type of rear quarter panel/rear bumper armour also helps. Sliders are an absolute must as you will come down HARD on rocks. After recovery points, sliders should be upgrade #1 for crawlers.

Clearly lockers help, although LR ETC is an effective system provided 1) adequate suspension travel, and 2) effective use of brakes. You WILL get tires in the air, which is where the lockers come in handy.

Finally: expect some body damage. This is critical, or you'll be miserable and have a bad time,,,and, hey, the whole point is to have fun, right? Don't even bother if you don't want "Rocky Mountain pin-striping", based armour, scraped diff pumpkins, radius arms, rims, etc.

Cheers. Thanks Disco for a great series of threads.

[dent]

LOL i thought this thread was about rock climbing... well it is i guess but not the rock climbing i had in mind.. was all excited someone on this board climbed too....
take care
sam