vibrating when under throttle

You may have a u-joint going out, check the u-joints. Another area to check would to inspect the flex plate that the torque converter bolts to, check for cracks, and check the torque converter bolts.

Thank you, I never thought to check the flex plate.

It is hard to see the cracks if it is cracked. Looking for little black fine lines, but I'd check the u-joints first for play and it is best to take the driveshaft out to inspect the u-joints as you may not find play in them but you would notice that they do not move freely.

Your talking rear shaft correct. Since in 2 wheel Dr the front shaft don't turn. Am I correct on that?

Yes it would not turn. If the u-joints where frozen up in the front axles, you would notice it in the steering. The front driveshaft you would noticed when in 4x4.

Oh ok I see now. Your talking axle ujoints. I'm sorry. I had a blond moment.

So check the rear driveshaft u-joints.

Ok. Great. Thank you.

Could front brakes and rotors cause this as well or would that make a constant vibration?

If you had warped rotors, you would feel it when you break only. This is sounding more like front wheel bearings. Jack up the front and spin the wheels to see if you hear any noise. Pull back and forth on the wheel to check for play. Look for rust by the axle nut.

Ok thanks. I'll try that next.

Every thing looked and felt pretty tight. All ujoints looked good. I guess I'll just take it in somewhere and have it looked at. Thanks for your help.

morning i have a 2012 F 250 heavy duty 4x4 lariate truck I was driving this morning to work got on the free way speed up to 70 75 miles and suddenly I felt a shaking and loud noise so bad I pulled over thinking it was a flat tire yet it was not so. What can it be. It seems to be exactly the same noise when I actually had the flat tire last month.

morning i have a 2012 F 250 heavy duty 4x4 lariate truck I was driving this morning to work got on the free way speed up to 70 75 miles and suddenly I felt a shaking and loud noise so bad I pulled over thinking it was a flat tire yet it was not so. What can it be. It seems to be exactly the same noise when I actually had the flat tire last month.

Hopes this helps someone. My 97 f350 vibrated very bad. I changed the hanger bearing and it got worse. After further inspection somehow the horseshoe shaped strap that holds the back ujoint to the rear end had a groove worn in it and it was not perfectly aligned. I changed the strap just to see and it rides smooth as silk now.