from the link you posted, "The 4-HI setting locks both drive shafts for extra grip and pulling power to give you confident handling on slippery, wet and graveled terrain."

Key words are drive shafts, the drive shaft engages the front wheels from the transfer case.

You need an LSD or Locker (front and rear pumpkin) to actually lock all 4wheels to get equal power to all.

 

It's the same transfer case (NV243) as the Jeep Wrangler (NV241), except it is electronically controlled. When engaged it distributes power equally to front and rear drive shafts. Definitely don't want it engaged in either 4HI or 4LO on pavement.

You also have the electronic Traction Control System (TCS). It's a brake-lock differential of sorts. The electronics will apply a slipping wheel brake for you. Works pretty good, but it is probably pretty hard on the brakes if you use it a lot.

I also have a Jeep Wrangler Rubicon with electronic diff lockers. The drivelines are comparable to the Ram - same transfer case internals and open diffs when the lockers aren't on. I've experimented using the TCS vs having the lockers on . The lockers are superior for sure, but the TCS actually works about as good as a limited slip diff. It works in both the front and rear so you get gobs of traction if you need it.

Bottom line is even if you don't have an LSD in the back, you have far better traction than open diffs of a few years back!

 

sweet. thanks AZ!!! thats really well explained. so whats your sayin is ill be able to handle the michigan snow......

sorry, but my sport wont be seing any trails anytime soon.....

 

Yeah, you guys are right, it's not the differentials that lock, just the transfer case.

 

The only way for a differential to lock up is if its a locker, and no 2009 1500's came with lockers. Also many of you are missing the traction management system on this trucks. I'm not a huge fan of it, but it does help increase traction with the open diffs but applying brake pressure to the wheel with less traction. This simulates traction and forces more power to the other wheel. Its no locker but i have found it to perform almost as well as an LSD.

 

I recently purchased a 2010 RAM 1500 4X4 and had an opportunity to try it on Christmas day here in the Metroplex. Roads were wet / icy and no issue(s). I gave my wife a ride to work this morning as roads were still icy in many areas.

When I pulled into the parking lot where she works, I felt my wheels start to buck....I understand the mechanics of why, but I thought 4x4 hi had some limited slip to it.

So now, I want to know and fully understand how my 4x4 system works so I don't screw it up. Sales guy made it sound like 4X4 hi as the option for added traction.

Any thoughts or insight on 2010 4x4 lonestar edition would greatly appreciated.

 

it's for 2011 but the same

 

2010,

When you do a full turn the inside wheel is rotating less than the outside wheel which causes the bucking sensation you are feeling.

4WD LOCK
Four-Wheel Drive Lock Range - This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. This range provides
additional traction for loose, slippery road surfaces only.