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Can someone please explain hill descent and traction control?

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dm6

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I was reading about these in the manual and I guess I would just like a better explanation of these two things (and any other similar features) work in real life. I doubt I will ever go off roading so I would be more interested in how these may apply to snowy or slippery conditions. Also, if I understand correctly, the anti-spin differential will spin both wheels if it detects one is spinning, correct? What about the front wheels? Will those both spin as well, or just the one that has traction?
 
Hill decent just keeps the transmission from coasting, allows the engine to keep vehicle speed slowed down when you don't give it fuel. Your traction control will allow both wheels in the rear to spin as long as you have the anti-spin rearend, I don't think Ram is selling an anti-slip in the front so it will always turn the one easiest tire.
 
DammitDave said:
Hill decent just keeps the transmission from coasting, allows the engine to keep vehicle speed slowed down when you don't give it fuel. Your traction control will allow both wheels in the rear to spin as long as you have the anti-spin rearend, I don't think Ram is selling an anti-slip in the front so it will always turn the one easiest tire.
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Maybe I am thinking of something else. What you are talking about is evident when I am going down a long grade and it doesn't keep accelerating when I am not giving it gas, right? I think I am talking about the button that is around the shift knob where the 2WD and 4WD selectors are. It sounds like that is just used in 4L?

As far as the traction control, I have read in different places where it may be advantageous to turn it off in snowy conditions and I don't quite understand why.
 
Not to sure I can help, I have a Tradesman with manual shifters. But I do know sometimes when you are in mud you need wheel spin to help keep forward momentum and that is when you would want to turn the traction control off or maybe if you are stuck in snow and trying to fight your way out.
 
hill descent is a very cool feature. it essentially will allow you to go 1mph down a steep hill. it controls the braking so all you have to do is steer. it flat works. it uses the brakes but controls them so unless on pure ice keeps your speed where you want it. first gear=1mph 2nd gear =2mpg etc. it really is only useful when offroad tho. traction control is just that your truck alternates braking etc to keep traction. Traction control is used in everyday driving. it can be irritating at times tho as sometimes you want to spin your tires and traction control will apply the brakes.
 
jadmt said:
hill descent is a very cool feature. it essentially will allow you to go 1mph down a steep hill. it controls the braking so all you have to do is steer. it flat works. it uses the brakes but controls them so unless on pure ice keeps your speed where you want it. first gear=1mph 2nd gear =2mpg etc. it really is only useful when offroad tho. traction control is just that your truck alternates braking etc to keep traction. Traction control is used in everyday driving. it can be irritating at times tho as sometimes you want to spin your tires and traction control will apply the brakes.
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Ok, I think I understand it now. That makes sense that hill descent wouldn't work on an icy hill because you would just slide anyways, but I see how that would be useful going down a really steep dirt hill.

So for traction control, if you were stuck somewhere in snow and needed to get the wheels spinning to try to get it to move, you may want to turn it off to create spinning but if you are not stuck and just driving normally on snow where there may be some occasional slipping, you should just leave it on. Does that sound right?
 
Hill decent only works when in 4WD low. You then use the gear up down to set your speed.
 
dm6 said:
Ok, I think I understand it now. That makes sense that hill descent wouldn't work on an icy hill because you would just slide anyways, but I see how that would be useful going down a really steep dirt hill.

So for traction control, if you were stuck somewhere in snow and needed to get the wheels spinning to try to get it to move, you may want to turn it off to create spinning but if you are not stuck and just driving normally on snow where there may be some occasional slipping, you should just leave it on. Does that sound right?
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Yes that the basics of it for traction control it also helps save the rear brakes
 
jadmt said:
it always amazes me how well it works. In moab you can be almost vertical and never have to touch your brakes. Takes faith to use it the first couple of times :).
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That is true. Ive used it on the power wagon a couple times and its freaking awesome

Sent from my SM-G996U using Tapatalk
 
dm6 said:
What about the front wheels? Will those both spin as well, or just the one that has traction?
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The front axle (assuming no brake-lock differential / traction control) will spin the one with the least traction, not the one with the most. An open differential has no way to bias torque, therefore the rotational just wants to escape by means of the path with least resistance. The tire on ice has the easiest escape path compared to the other on snow, so it will transfer very near to 100% of torque to the ice tire.

Now in the case of the modern FCA traction control works as a brake-lock differential in that it uses the individual brake calipers to apply resistance to the wheel spinning and create a new path of least resistance that would be the tire with greater traction. The system is not equal to an E-Locker differential, but it is way better than an older non traction controlled open differential that wasted the available torque on the most useless wheel every time and all of the time. The difficult thing with off-roading with the brake lock diff is that you have to learn to apply mild throttle to maintain spinning tires while the traction control plays with the brake calipers for sometimes a few seconds before it really solves the traction problem. I've been out with guys in stock driveline Jeeps and often they want to lift throttle when they start spinning. They have be told that the Jeep will solve the issue if you hold steady throttle and let the computer play and solve the traction issue... assuming that there is enough traction somewhere to solve the problem.

Nothing beats a real E-Locker, ARB air locker or Detroit mechanical locker though. Next best (and not far behind) is a Eaton TruTrack... They are shocking and amazing if you can get the correct fluid in them.
 
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