We have an '04 V8 (full-time 4wd) and lately we've noticed a weird front end vibration when accelerating slightly, going up a slight hill. It's not the brakes, it's not the cv axles as we have had these looked at already. It's not out of alignment either. The tires are fine also. The truck has about 150,000 miles on it. Wondering if anyone has had a similar experience. Thinking it might be drivetrain related. Any ideas?