Why does 4wd Low have so much more traction?

[mathyou]

I'm curious about what kind of differential my truck has on it. Read my info to the left to see what truck I'm driving. The guy I bought it from changed the rear end just before I purchased. He told me it was a stock or stock equivalent part.

So, here is my observation:
When I get into a slippery situation with 4wd High, and put the truck into 4wd Low, it seems to gain a whole lot more grip and traction. What I'm feeling is that something more than gear ratios are changing. It appears to be more than just the wheels slowing down and torque increasing (which is what I assume 4wd Low does).

So, my question is:
Does this extreme increase in capability when in 4wd Low mean that I have some kind of trac-loc or other locking or ______ rear end? Or is this normal for all rangers or high and low 4wd vehicles of any type?

And yes, I have read the tech pages on differentials and searched the forums for posts on differential info, so forgive me if this is a repeat or silly question.

 

[BRUTUS_T_HOG]

So, my question is:
Does this extreme increase in capability when in 4wd Low mean that I have some kind of trac-loc or other locking or ______ rear end? Or is this normal for all rangers or high and low 4wd vehicles of any type?

no. are you sure 4wd hi is actually working? 4wd low just lowers the gear ratio

 

[85_Ranger4x4]

Nothing should be happening aside from you changing gear ratios. You have the most traction right before your tires slip, and the lower gearing lets you ease into all that much more.

 

[mathyou]

no. are you sure 4wd hi is actually working? 4wd low just lowers the gear ratio

Yes, fairly sure. I use it occasionally when climbing the steep gravel driveway and it makes a noticeable difference.

Nothing should be happening aside from you changing gear ratios. You have the most traction right before your tires slip, and the lower gearing lets you ease into all that much more.

Perhaps you are right. But the difference seems like more than slower turning tires.

 

[84stealthranger]

Unless its got some kind of electric locking diffs when its put in 4low that the OG owner put in. But I think its just what 85_ranger4x4 said and that u can do a lot more in 4low when dry then in 4 high cuz the slower speed and torque.

 

[kcm1582]

The reason 4x4 low has more traction is that it allows the tires to get a better grip on the ground by giving them time to settle and find something to grab on to. Think of it like trying to grab a greasy part, if you grab it quick (4 hi) then it might slip out of your hand, but if you slow down and grab (4 low) it then you get a better grip on it and it wont slip as easily.

 

[James86]

I used to get a similar sensation in my 99 Cherokee. In 4 low, the torque was so much greater that if I was on a drier surface or had decent traction it was tough turning the steering wheel at times. But I think a big part of that was how short the wheelbase was in proportion to width as well as the torque - it was a 4.0 with a 5 speed and CommandTrac so 4low was pretty low.