How many miles? Stock U-joints? just because they
seem good doesn't mean they are not dry and going bad.
I first noticed my bad U-joints when I was leaving a stop
sign and I heard a creaking noise from under the truck,
and ended up getting them replaced at a machine shop,
they don't cost much and a press, or a buddy with one
makes the job so much easier.
The best test, and it's good because you can feel the
shake or vibration is the speed of the problem, driveline
vibration is high speed, like a very fast buzzing, where tire
problems are much slower, like the speed of the turning
wheel.
You might have a bent rim also, something to check
Wild
