I have notice a change in my vibration problem since the weather has cooled off here in Maryland the past week or so. The first 15 minutes or so of driving the truck is very smooth, no bothersome vibe, but the vibration does come bask after driving for a while. Can anyone explain this? Could it be heat related somehow with the transmission or tires.

PALongbow

Have you noticed any change in yours lately?

 

If it were the tires, the vibration we be there at the start, and then go away over time. Since it's not there on yours and shows up after a time, then I would say it is heat related or something else that hasn't been discovered yet. Your transmission suggestion could be right. The vibration in my truck was resolved by replacing the whole transmission. (LINK)