Originally Posted by Jaytwo
4x4 lock is simply in 4x4 rather than auto 4x4. There is no locker available for the front of the half tons. It would quite literally destroy the housing.
agree! further explained: 4x4 Lock means "I wanna send power to all 4 wheels from now on until I turn it off", 4x4 auto means the computer gets involved and determines that once wheel slip starts the 4wd kicks in. But for offroading, a LOCKER means "I am going to send power to all wheels at the same rate (left and right sides) NO MATTER WHAT If they start slipping or not". 4 Wheel LOW is the "EAT S***" gear as I like to call it because if you need serious TUG power or more power sent to the front wheels instead of the rear tires then that's your set up! Caution though, stay under 10mph with 4WD LOW. 4x4HIGH you should be good up to 50mph or so but it shouldn't be on if road conditions are that nice that you can go that fast.
If you want to offroad hard enough that you think basic 4wd isn't good enough, get a Jeep with factory lockers (rubicon models) or drop a locker in the cheaper models because they still have solid axles (but most guys will upgrade even from stock Dana axles before putting lockers). Some other makes (toyota comes to mind) also have Lockers in their factory 4x4 set ups but not Ram 1500's. I used to jeep a lot but no way would i try taking my ram down the same trails as the ones I saw.
This may be common knowledge to most but since winter is here (or approaching for some of us) its good review and good info for those maybe with 4wd for the 1st time.