well we just got what was said to be a blizzard here in indiana and got to use my 4x4 in my new (old) 82 k10 specs are 350/sm465 tranny/np205/dana 44 front axle. everything suspension wise has been changed out through its life span. we got about a 16 inches of snow here and when i decided to goose it a little in 4 wheel and have a little fun i felt this really loud rumbling from the front. only does this if its under hard accel. did it a few times here and there under hard accel. tonight i had to pull a buddy to my house with a tow rope when taking off in low and giving it good throttle it would rumbl. so heres what i know ive done. new axle u joints both sides. has a new u joint at the yoke. the double cardan at the t case is good as far as i know. i will pull tomorrow and inspect anyways. fluid is topped off in t case and axles. has mile marker locking hubs aswell as bearings repacked and good to go. so i have a question. is it possible that where the cardan joint is the ears of the joint are hitting like i have axle wrap. it vibrates hard and rumbles like mad so thats my thought. would a transfer drop be needed. or what do you guys think?oh yah it doesnt make noise in 2 wheel so that rules out the rear end and tranny etc.