Bushtracker Tip # 16, Extreme 4x4 - Diff locks priorities...

Submitted: Saturday, Jan 15, 2005 at 01:48
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This one is a hint for both Newbies and Veterans. Steven Gibbs here, and I thought I would continue on with some practical tips for off-road travel with vans that you might not read about anywhere.. These are practical, and born of the experience of doing it the hard way to learn how to now do it easy...Ha!

This one is on the best use of Diff-Locks.. (I digress a moment for those that don't know what Diff-locks are....) This is the differential locking device that locks up both wheel evenly... Without it, most 4x4's will just transfer the power through the differential to the least loaded side (and the one that is in the bog just spins while the other on firm ground just sits there doing nothing) Ha! Now a differential is necessary to allow your drive axles to go around curves so the outside wheel can turn more than the inside.... However, it makes most 4x4's in the mud only sort of have one wheel driving in front and one in the back, if two of the wheels are slipping you have nothing and "Bogged" again...

My second most important piece of off-road gear is the Diff-Lock. It locks up both to turn evenly... Can't run on the road obviously, this is only for in the soft stuff. All or nearly all tractors have this so they can run around in muddy paddocks ploughing... Anyway... I have one ARB Air-locker in the back of my 89 Sahara and a beefed up LSD in the front..(Limited Slip Diff)... The beef up of an LSD is the second best option, and is accomplished by a good Off-road Mechanic by shimming the springs on the LSD clutch pack. Usually they go in the rear, and the clutch packs have a limited life... You can only put one of these in the front if you have the after-marker lock out hubs like I have on my Sahara, and like I added on my Ford F-350 (Yes they still make them- Mine were from Warn). The LSD would be dangerous to steering if you did not have the lock out hubs in the front... Now on my 100 Series, I have the ultimate: Diff-Locks front and rear... But that takes talent to drive, as in the mud with both wheels turning and biting in the front, as one wheel grabs some firm ground it will lurch and over-steer in that direction... Let me emphasize that point!!!! In off road conditions, the front Diff-Lock is the greatest, but you have to learn how to gingerly drive it or you will hit a tree.... With both wheels grabbing mud, as one gets ahold of some serious traction it will pull the front end that way and oversteer... You have to take it slow and careful... But I have to tell you that with all four locked up, my 100 Series Cruiser will darn near tow another Cruiser where it could not go by itself with standard slipping differentials.... It is a real Beast!! And ARB Air Lockers are the King, as you can selectively turn them on or off with a flip of the paddle switch.... So, in most conditions, you would not run down a greasy track with the front Locker engaged.... OK?

Now to the general Tip: Don't use them going in..... Simple as that !!.... Off road towing means that sometimes you are lazy and don't get out to walk suspect ground.... And sometimes you are fooled by a dried crust on suspect ground... And I have been fooled for instance on the Gregory River in North Qld by dry river gravel that was smooth, mossy, and very wet little greased ball bearings underneath as I broke through the crust with my 20' Bushtracker on the back.... Now my tip is in general, save some ammo... Have some reserves, don't use the diff-locks to get in if it is that bad, because if you get in the poo too deep (and I do), then you need to have reserves to back out of a bad spot.... If you inadvertantly go in to bad slick ground, and quickly stop before you make a mess of things, you can "Lock Her Up Baby" and have double the traction to gingerly back out slowly in low-range without breaking traction..... This smart move has kept my boots clean many times as I got older and smarter... This will save many of you if you stop immediately when you are in trouble before you make a mess of it, and "Lock Her Up" and back out of trouble slowly, again without breaking traction you will have twice the grab and can easily get back out.... But, not if you use the Diff-Locks to just get much further in the poo... Then you better just set up camp and make a cup of tea... Ha!

Now there is an exception to that rule: There are places where you can see that you are going to get into the BOG... But you can see the other side.. For instance I remember one occasion on the shortcut back track from William Creek on the Oodnadatta sp? anyway the short cut over to Coober Pedy is quite a nice track from William Creek... But when I was last on it there were BOGs about 10-20 Metres long.... Only a half dozen in 20 kms or so of the 115km shortcut.. But... With a 20' Bushtracker on the back and no way to get around them, you just have to pull your hat down tight over your ears, and tell em to "Open up the gate" and just "let her rip" !!! Wish I was a Rodeo Cowboy but too old, Ha! (Translation): That means Yes, diff-locks in, all youv'e got, and Low Range on the Transfer Case with a powerful gear like third with good rpm (depending on your vehicle) and a gear that won't BOG down... No pun intended. Ha! And in that case you just hit it with a little run, not to fast to throw mud and water over the bonnet onto the windscreen, just a bit firm and powerful... And you keep your boots clean with the extra pulling power of the Diff-Locks... As the secret to short runs through bogs is Diff-Locks and keeping up the momentum... And ARB Air-Lockers are the only ones that are selective, in when you want, out when you don't... I even have them ordered in my Mack, Not ARB ones, but anyway, diff-locks and transfer case lock.
Go-anywhere security...

Happy Trails, in the words of Roy Rogers,
stg at Bushtracker
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