four wheel drive problem

well it just started snowing like crazy here in toronto, ontario and i happen to put the four wheel drive on, and it was making like a humming noise when i push the gas. has anyone had any problems like this? when i bought the truck last year i complained to gm about a schreeching noise when in four by four when you steered a little to the left... the foreman who supposedly had 30 years "under his belt", told me that when in 4hi you can drive only to a maximum of 30 kilometres and the steering wheel can only by turned to a maximum of 30 degrees each way.........have i been cheated? can anyone please help me... what is the maximum kilometres i can drive and can the steering wheel be turned all the way??? Is this humming noise normal????????please help you guys.....thanks...

It's not normal, I can drive pretty much as fast as I want to in 4-HI, although I try to stay under about 45mph, and the only time you should have any problems turning is on a hard flat surface, like pavement.

Hey Take It To Another Shop It Is Not Working Right

Oh Talk To The Shop Foreman Or Manager
If They Say It Is Normal. Tell them You Would LIKE To Ride In Another Truck So You KNOW It Is Ok And The Biggest Dealership Secret Is For The Customer To Raise Hell And You Will Get The Right Answer For Someone But Always Calm Down Later :evillol: Once They Try To Help Ya