Southern Comfort

My truck is a 2008 Silverado 2500HD LTZ crew cab 4x4 with a 6.6 Duramax. Has a 6" lift with 35x12.50x20 tires. I have had a slight vibration for awhile but has recently been getting worse. Speeds I notice the vibration is 30-35mph and above 55-60mph. When in 4wd Hi, vibration is much worse above 15-20mph. U joints in rear and front shaft have been checked and are fine, rear diff seal replaced and gears checked and are fine. I do have an inner tie rod and lower ball joint being replaced tomorrow and 4 new shocks being installed. I thought maybe output shaft bearing on the transfer case but no leaks from the transfer case have been seen. Any and all ideas you have will be helpful. Thanks in advance!!

oldchevy

Have you checked your tires? They can get out of round and cause vibrations.

Southern Comfort

Tires have only been used one summer. Alignment done when they were put on. I use smaller narrow tires for winter on 18" rims. My mechanic is checking wheel bearings today as well as the other repairs he is doing. Can actually "hear" the vibration humming with the windows up and radio off.

oldchevy

When my 2013 did that it was the right side wheel hub. It only lasted 5 years.

Irish_alley

in order to cause a vibration it has to have rotational energy. no tie rod/ball joint will cause this, did it do this with your old wheels? like stated it could be a wheel hub
does it get worse/better when brakes are applied? could be a cv axle also

Southern Comfort

Ok, so today I had all the work done on my truck. Tie rod, ball joint, alignment, and they also replaced my old shocks due to a blown out shock with new Ranchero's. They also told me they found where my front drive axle was rubbing on something metal due to whoever put the lift kit in my truck. They made a bit of clearance between the axle and whatever it was rubbing on and vibration seems to be better. I didn't drive it far after getting repairs done today so will give it the test tomorrow to work and back (20 miles round trip). Vibration did get worse when I went from the smaller winter tires to the 35's. I will do a hard acceleration from 30-70mph tomorrow on my way home. Usually is noticable accelerating hard climbing up near 50-70mph left in 5th gear not letting it shift to 6th. Will see what happens tomorrow.

Southern Comfort

Still has a slight vibration but not nearly as bad. Vibration was a lot worse in 4 wheel drive last winter than in 2 wheel drive. My guess is something in the front end or transfer case?