So I've been battling this vibration issue for what seems like forever, and it is getting worse. I have ruled out the front end as it is perfectly tight and aligned. The universal joints are new and all the weights are on the drive shaft. If you set the cruise at any given speed, the vibe will come and go. I just got my new tires on yesterday and it was the same with the old tires, so I know it is not a tires problem. I even swapped the old tires onto my friends silverado to see and it drove smooth right till 140km/h.
But then I noticed, there is play when you grab the drive shaft and try to move it, but at the transfer case. I would say there is about 2-3 mm of play there, you can definitely see it move. So I have a few questions:
1. Could this be causing the wobble at 65km/h~, and the vibe I have at 90-130kmh (it probably does it at higher speeds but the frequency is so high that it is not noticeable).
2. Can this be fixed on the truck?
3. Is it something I could do or do I need special tools (send it into a mechanic)?