2004 Silverado Z71 4x4 5.3L Vibration issue
 

Having an issue where the front end vibrates. Removed transfer case to front differential drive shaft and CV axels to front wheels to try and isolate the issue. New tires within the last year, swapped in new wheel hub/bearing assembly's, rotors, calipers, brakes, and sway bar linkages on both sides of the front. Still having issues when reaching 40+ mph. Vibration seems to increase when throttle is released. Does anyone have any ideas what it could be? I will be making an appointment tomorrow to have the tire balance checked.

If the tires are in balance, have them rotated anyway and see if it follows to the rear. It could be a defect that may or may not be visible (such as a bulge) but isn’t affecting balance either.

Check mounts for the motor and transmission and verify fluid level and condition in transmission as well.

It may also help to have the alignment checked. Alignment being off won’t directly cause a vibration, but the suspension components that wear out due to misalignment can.