Anyone know the difference between auto 4x4 and 4x4 hi? like how does it work? same gearing? mph limits? turning radius? etc.

 

4hi locks your front hubs all the time - auto only locks them when slip is detected. Auto 4x4 is safe to drive on pavement AFAIK, 4hi is not. Same gearing.

 

Aren't the hubs locked all the time on the IFS trucks? The autotrac engages and disengages the front diff. when rear wheel slip is detected. And Four HI/LOW locks it in.

 

correct. I broke my lock back when I had my 5.3/radix combo. I had it auto on a rainy day and nailed it. All it is a plunger that pushes an axel spline coupling over the left side of the diff. Don't know the technical terms, but a pretty simple operation.

 

so is it bad to use autotrac then? i like to use it in the rain for launching.

 

Don't use it for launching - just choose 4 hi. It takes a certain amount of slip before it engages - you don't want any slip.

 

Does Launching In 4 Hi Hurt Anything.

 

No, I do it all the time at the track and some times on the street

 

these threads pop up every now and then. Some one will always argue launching in auto 4 is fine.

If you're questioning launching in 4wd, you obviously dont want what... slip. And like thunder550 said, when you launch in auto 4 it has to slip before 4x4 engages.

 

well what i do want is the ability to drive around in the rain/snow without worry about traction or driving on dry spots, and without worrying about breaking anything. if the only downfall of using autotrac is slippage, it sure as hell beats one wheel peel im not looking to race here, my transmission cant handle that right now anyway, just dont want to drive like a grandma at a stop light.