my 01 2500 drives great in 2wd, but as soon as i engage 4hi and hit the gas, a loud continous grinding comes from the front end, as soon as i left off the gas the noise goes away. and i only use my 4wd in the snow(fairbanks, ak) i cant figure it out. any ideas?

 

Sounds like your axle joints.

 

when my joints were bad and i had it in 4-wheel drive, they would make a loud clanking like noise when the front tires would spin.