Question about axle ratios

If you are mostly off road with ball-buster loads, those gears would be fine. It saves on the clutch too.

 

If you’re going to be off road the 5.17 will be what you want. Not like you’re going to spend much of any time in the big hole. I run 4.33’s and sometimes that ain’t enough

 

No.

Your engine puts out a specific amount of work. Torque is one of these, a value of work from rotation against a load or inertia. If you have good engine and casterated it with crappy 1.60 gearing then it's yourn fault when it stalls out under you. But you can have a tiny lawnmower engine with about a 1000.5 gearing (It would be around 4 feet tall..) and you can move 500 ton. Not very fast but you would move it.

 

No. Ratio means rotation. If you put a little tiny gear with a 600 Red Cummins on it rotating 1500 times per minute against say a big gear, it will take a minute or two for that big gear to come around one time.

That's where the transmission comes in to play. You are picking a drive ratio that will turn that little gear faster so you can get somewhere with that big rear end gear today sometime to keep your dispatcher happy.

I cannot ... *Hunts for words.. dumb things down (Not offense against you or anyone, just a thought of concept of ratio, drive and speed) any further.

Now the other side. If you had that big red cummins turning a 2 foot wheel gear at 1500 and put it on a tiny gear in your rear, you are going to have a 300 mph truck. You could try to slow it down to something useable with your transmission. But try to carry a bag of groceries on that tractor it will just fall down and stall.

The easiest visual I can think of is NASA's Launch Crawler. It's top speed is about .9 mph and it has a gear tower that makes each of it's two electric driven motors rotate 168 times for every one rotation of it's GIANT tread gear.

 

Single axle 5th wheel trucks are nearly useless off a hard surface if they do not have some weight on them. An axle lock helps a lot.
Many short wheel base tandems with a set back axle turn very well.