Okay, Every review about the 750 claims it as being 4WD on the fly, but the manual says I need to stop to switch it, otherwise I could damage the front drive.....whats the truth on this??

 

A couple of guy's I ride have 750's and if they are stopped and put it in 4wd it will not go in. They have to be moving for it to engage.

 

I have a 06' 750i and I have went from 4wd to 2wd and vise-versa while driving all the time and it hasnt hurt mine at all. You will hear it engage though in the front end.

 

you don't have to be completly stopped but under 25km/hr i believe. A little tip - atleast what seems to work for me - don't put it into 4WD when you are on the throttle, it doesn't engage very smooth. It works best if you are "coasting" at any speed below 25km/hr. If you are stuck in a hole in 2WD then it is almost impossible to do this because your back wheels won't be moving unless you are on the gas. Therefore, if you plan on playing in the mud it might be wise to put it into 4WD before you get dirty.
My .02