vibrates

I've recently noticed some vibration when driving my 2011 Yukon Denali at slow speeds. It usually happens when I'm cruising anywhere from 20 mph to 45 mph, RPM is at 1000. When I slightly step on the gas in between gear shifts, I get a quick vibration that lasts a second or however long it...

I have a 2007 GMC Yukon Denali. Everything is stock. 90,000 miles. Tires are about 50%, brakes are good, alignment is good. When I'm traveling above 60mph and let off the gas it vibrates hard... just like going over rumble bars. It has that feel but not quite as much noise. This is the only...