Originally Posted by llsht14
The 4x4 auto is one of the reasons i sold my 1500. The 4x4 auto works good like it should. but in trucks with the 4x4 auto option the 4x4 lock option doesn't actually lock like it would in trucks without the auto option, its the way the transfer cases are set up.
What do you mean the truck doesn't actually lock?
From my experiences, the 4wd lock means your transfer case is "locked" into 4wd and is constantly transferring power to your front diff just as it is your rear. When the snow is really flying or roads are extra slippery, I use this option.
4wd Auto, as others have stated, is automatically transferring power to your front wheels as it senses your rear wheels slipping. I find in my ram there is a pretty solid delay between rear wheel slippage and front wheel engagement. You can get pretty squirrely before your front wheels start to pull and straighten you out. Not really sure of ratio of rear spin to 4wd engagement. I use this all winter when it's not super bad out because you're basically driving around in 2wd unless you start to spin.
I can't see any issues with exceeding 55 while in auto.. the only problem would be if you somehow started spinning and the 4wd engaged at these speeds. For one it would cause some pretty unpredictable results and two I'm sure it'd be pretty stressful on your drivetrain at that speed, especially if you then caught traction again.
Just my 2 cents...