Vibrations from 15 mph up?

I have a 2001 Ext Cab 4x4 with 6.5' box, 4.8L engine, auto-trans, and Michelin LTX 245/75R16's. I have had a vibration (while driving 15 mph and up) in my truck on most roads since this truck was new. The vibration is felt mostly on the steering column (wheel) but you can feel it on the floor and IP. Mechanics say some vibration on this type of truck is normal, right! The dealership spent several days driving around trying to isolate the problem and came up with tires as being the culprit. They put two complete sets of the OEM tires on the truck and they eventually put 4-Michelin's on, which eliminated some of the vibration, but not all of it disappeared. They said that was all they could do. I gave up on looking out loud, but 27,000 miles later and the vibration is still there. I'd like to find out what else might be the cause, I really don't think the tires are the whole problem. If anyone has experienced similar vibrations, please reply! :(

I just bought a 2000 Silverado Ext cab (3 door) from my dad, it has 5.3L, 2wd and only 31k miles. I have noticed a vibration from 15-20mph while acceleratingg but have yet to figure out why. Did notice it more when i rotated the tires so this weekend I will rotate them again. Other than that I have been looking around the forums to see if others have had this problem.

The extended cab trucks seem to be more likely to have the vibration problems and especially if they're lowered. The pinion angle is pretty critical on these trucks. There are shims available to tilt the pinion to the correct angle. You might want to have this looked at. Hope that helps.

I put aftermarket wheels on my 00 silverado 5.3 and it started the exact vibration that you had. So i took it to a professional alignment shop and they did a perfect alignment and took it back to the tire shop and they did a complete wheel balancing session. Since then perfect ride with very minimal vibration. You should check into it. Hope it helps

Thanks!! I will have the tires balanced and maybe an alignment. The truck is stock, nothing has been modified or lowered. Other than the vibration it runs great. I have been a little surpried with the gas mileage, drove from montana to minnesota and was getting 23mpg, in town it has been 19-20mpg. Didn't expect it to be that good with a 5.3L.