holy crap video

[philipatmaxfour]

Holy crap video

All Argos have open differentials or they wouldn't be able to turn, and just like a car with an open differential the power and torque always seek a path of least resistance, so when you are going straight and are on the same type of ground the resistance is the same so both sides push the same amount, but if you encounter less traction on one side than the other then that side is the side with the lesser of resistance and will spin while the other side does nothing as all the torque is routed to the spinning side, as illustrated in the video here and countless other places. Simply braking the side that is spinning will just bring it to a stop so it is temporarily equal to the already stopped side. When you try to go again you are right back to where you started with uneven resistance between the two sides. If you could lock the diff at this point then you would send the same amount of torque to each side and the stationary side would now have the ability to move and help get you unstuck. As far as the other machines that use the T-20 and hydraulic drive, they don't have differentials because in effect they have two different transmissions, one per side, so they can control each side independently and vary the amount of torque and speed for each side, resulting in the ability to turn due to the speed difference between the two sides. If one side loses traction it has no affect on the other side because the other side is not connected to the spinning side, they are independent of each other, unlike the open differential that the Argos use.

I hope this is clear, I don't know any other way of explaining it and hopefully an Argo expert can set me straight as to why Argo don't have the option of a lockable diff.

Wow! I'm glad that you explained this to me.I had no idea.

[beagle man]

I don't claim to be an expert on the subject but the operator made a good move staying out of the water but he may have been going a little faster than he should have. I owned a 2002 6x6 conquest Adair tracked for 3 years and the only times I had issues with getting stuck was going too fast into the unknown and I did manage to get 3 out of 6 tires off the ground. The transmission will turn both sides with some feathering of the sticks (it takes a little practice but becomes second nature) on the older rigs. you do need to be creative if you play in the bush, if you bring a couple items to stick in the ground the machine can pull its self out by hooking on to the track grousers and driving the tracks.

[Coast2Coast]

an Argo has no "differential". Yes you find those in cars and trucks but not these machines.

The gearbox contains an open differential, that is what allows one side to stop when the brakes are applied. The new admiral "triple differential transmission" has 3 of them. Applying the brakes to one side is the same thing that happens when you get stuck in the mud, the mud becomes the brake on one side and that side stops. When you're running tracks you'll see it with your own eyes. You'll see that one side always stops spinning when you're getting stuck. You have to brake the spinning side to transfer the power over to the stuck side. But the balance is tricky, and sometimes you end up only able to power one side at a time.

For that reason being able to lock up the differential would certainly be a big help getting you out. But there are a lot of problems to deal with. One problem is the way you need to engage the system. There is a pin that has to move into position to lock the diff. In my off road trucks, much of the time I have to be moving to get the differential to lock. I have to cut the wheel and drive it a short distance so that the wheels on opposite side of the diff travel a differing distance, cause the diff to slip and the pin will line up with it's hole and "click" it will lock into position. If you wait till you're stuck to lock the diff, now you're only option is to actually start to spin the tires under power to get that pin to line up inside the diff and snap into position. This leaves the possibility of shearing the pin off or grenading your differential. It is the same thing to disengage it, you have to reach a moment while moving that there are no forces acting on the differential so that the pin can slide back out. You could be in a situation that you could not get the diff lock to disengage and you'd be stuck sideways on a trail with no steering. A better system would be a small internal brake system inside the diff that locked the diff and could be applied with a lever on the handlebar like a regular brake for momentary use. But that hasn't been invented yet. What we have with the method of applying the brakes on alternating sides is the same concept as "electronic limited slip differential" in trucks. In that case instead of the operator pulling on the levers alternating, the ABS system, traction control system and the ECU are working together to apply the brakes alternating from one side to the other. Anyone who has used both will tell you that the locking diff is far superior. A limited slip requires one side to be spinning in order to operate, but once one side is spinning you are already stuck. That little moment of where your tire is not quite spinning but you are just barely grabbing enough traction for the machine to start moving is key. Remember from 121 physics, the coefficient of static friction is greater than the force of dynamic friction and the locked differential takes advantage of that little tiny bit of traction while the limited slip can not.

Another problem is that the forces that the powertrain would have to overcome on a badly stuck argo with a locked diff would be astronomical. Look at what is happening in the video, he revs it up and one track is spinning so he brakes that side to try and get the other side to spin. But the engine just bogs down and neither track spins. If he had a locking differential and locked it in this situation it would be the same thing as applying both brakes and giving it full throttle. The machine would eventually tear itself apart. So in the interest of reliability argo could never release a machine that could cause damage to itself in this way.

[john swenson]

i'm thinking if they had some rope, they could have scrounged some logs from over in the woods. lash 3 logs together like a teepee frame with one log angled into the ground toward the machine. hook the winch ( if it worked ) to the lower part of that front log. as they begin to winch it may have dug that pole into the ground enough that the machine would pull out. may have taken a few tries but it would be a on the spot '' land anchor '' . johnboy va.

[johnjr]

This video is a real disheartening eye opener for me.I just got my first Argo, 8x8 avenger 30 hp kohler, for hunting in Maine. I have a huge bog we hunt in and as I get older (55) just can't drag deer out of there. I was hoping after this season I would get tracks for it. It doesn't have the admiral transmission, so I won't waste my money on something that can't pull both tracks at the same time in a jam. I bought it used so it is what it is. I have had fun going into the river and just playing around, but I really thought I would be able to go through bogs similar to the video without fear that it would only spin 1 side at a time in a jam. By the way I am a heavy equipment operator for a living, and even a dozer or excavator will turn while still putting power to both sides. That's why Mudd Ox uses Hystat. I also have a Polaris Ranger and Sportsman that when you put in 4wd you have locking diffs. Not sure what it costs but is standard, because when you are stuck you need everything pulling! I still love the argo, will keep looking for a used 8x8 with admiral trans.

[Coast2Coast]

I wouldn't let this video discourage you johnjr. This video is not even close to representative of a typical argo trip, it is an absolute worst case scenario. I hunt some of the most desolate land in the world with my old conquest and my new admiral. We spend weeks at a time in places you could not walk out of, so our lives literally depend on these machines and they do the job just fine. Regardless of how the transmission works, they are still amazing machines.

[allwheeldrive]

It just accrued to me how they could have gotten out.
Ever seen a Soviet WWII era tank?

They always had at least one large log on the side

How come?

If the tank got stuck (and tanks will get stuck a lot easier than an argo with tracks)
What you do is chain / cable the log lengthwise between the two tracks at the very top of the first wheel. Than when you go forward the track or tracks drag the log up under the vehicle acting like a giant plow. This will get any machine away from being high centered. In fact as long as you have the power to pull the log through the muck you are essentially guaranteed to at least move your own vehicle’s length. Obviously you have to disconnect the log and start over when it gets up to the back of the tank / machine.

http://www.militarymodelling.com/sites/1/images/member_albums/42220/666565.jpg

http://f1.media.brightcove.com/8/77374810001/77374810001_3212222460001_amphib-tank.jpg?pubId=77374810001

In WWI the Mark IV tanks could actually spin the log all the way around the tank thanks to steel rails and a long chain. Obviously turning wasn't possible but considering the speed and point of the first tanks this was acceptable and made it unstoppable. Correct name being "unditching beam"

https://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/MarkIVTankWithUnditchingBeam1917.jpg/800px-MarkIVTankWithUnditchingBeam1917.jpg

[Craig_B]

It just accrued to me how they could have gotten out.



What you do is chain / cable the log lengthwise between the two tracks at the very top of the first wheel. Than when you go forward the track or tracks drag the log up under the vehicle acting like a giant plow.

That's brilliant!

[allwheeldrive]

Thank! I can’t believe I had forgotten about this trick. I’m always amazed by the cleverness of early post industrial man. So many things we consider annoyances of contemporary living where solved long before our time and sort of lost to history.
Given the same tools and problems there is no reason man wouldn’t have figured things out before my time. Mud, tracks, and logs all existed 100 years ago, so did getting stuck lol.
I’d think a length of heavy duty square ABS / thin walled Aluminum tube or just some cheap pressure treated 4x4 post would work at our scale. Take note Steve for the Jugernought ;-p

[scimanstev]

Very cool idea. However, assuming that somehow I manage to get stuck, I can't imagine a situation where my land anchor couldn't get me out, but I will always remember that as a plan B.

I am way to excited about Juggernaughts arrival Saturday to do much work today and tomorrow.

Steve

[mowbizz]

Very cool idea. However, assuming that somehow I manage to get stuck, I can't imagine a situation where my land anchor couldn't get me out, but I will always remember that as a plan B.

I am way to excited about Juggernaughts arrival Saturday to do much work today and tomorrow.

Steve

What are you using for a land anchor Steve?

[john swenson]

allwheel, i've seen a video of a fellow doing that same thing on a really stuck farm tractor.... took him right out !! j.b.

[scimanstev]

What are you using for a land anchor Steve?

I bought one from Amazon. Saturday I'll get it out and quickly assembled to take a picture. It is specifically designed as a land anchor. It comes in a neat carrying case.

Steve

[philipatmaxfour]

holy crap video

allwheel, i've seen a video of a fellow doing that same thing on a really stuck farm tractor.... took him right out !! j.b.

Right John. I saw a video where a 4x4 post,about 2 feet longer than the tire diameter, was strapped to the side of the tire and as the wheel slowly rotated the tractor sort of hopped on that side but drove the tractor out easily.

[mowbizz]

Yeah....never thought of land anchors but after googling it there are quite a few out there!