front end noise

Today i noticed a "tapping" sound couning from the from left wheel. it happens in the same spot of the rotation every time once per rotation. it does it in 2wd and 4wd and when turning and going staraight. speed does not affect the duration on the noise. going very slow has the same length noise as 25 mph. it sounds like a turn signal blinking but only the tic not the tic toc. you can hear it with the window down until about 35 mph then the noise of the air is to loud. i have checked the tire and there is nothing in the tire like a nail or rock have no idea what this would be. the u-joint was changed about 3 months ago.

thanks
skog

does anybody live in the bay county, michigan area or the kalamazoo, michigan area. theses are the two areas I will be 95% this summer and was wondering if somebody could spare a little while on a saturday or sunday to help diagnose the noise and help me decide what the best action is to take on it.

thanks
skog