What could be the cause to my trucks vibration?

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. Wheel alignment will never, ever cause a vibration - especially at high speeds. Based on the concern occurring more when accelerating and then going away when letting off - and also based on your share that this is a lifted truck -- I am going to suggest someone check and adjust your driveline angle. If the driveline angle is too aggressive, you will get vibration on acceleration -- if you can imagine the body of the vehicle lowering slightly on acceleration (it's just physics!), this changes the angle of the driveshaft. The angle could cause a harmonic vibration during that time until the load releases and then shape of the angle changes. A good, intelligent technician at a shop specializing in lifted trucks should be able to recognize this concern and work with you to resolve it. If you want some shop recommendations - use the links here -- https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.