Just heard it today havent had a chance to get under it and look yet. I speeds up and slows down when I do I got a 2000 sierra extended cab 4.8 4x4.

 

Oh and one more question, what should my rpm's read at 60 or anywere close to that? Mines at at like 2300 at 60.

 

mine is at1900 rpm @ 60MPH with 3.73 gears 6.0/4L80E 4x4 and check your oil

 

Thanks im not sure what size gears i have I just got the truck 2 weeks ago. I think my overdrive went out or something im at like 2500 at 60. The clicking noise seems to go the same speed as my tires.

 

Rock or something in your tire tread?

Oh yeah, and to see if your overdrive went out... Put your truck in 3rd and get up to 60 and see what your RPM's are.

 

dont know about the clicking noise but in my 02' the RPM's are around 2000 at 80-85 mph.of course I keep a good tuneup,run synthetic oil,and it breathes good K&N intake

 

I got the K/N could use a tune up but i think its my overdrive

 

Check your tires for a nail or screw. Also look under the truck for foriegn objects stuck to the drive line, also check your wheels for fresh scratches if there are new scratches on the inside then something is rubbing it.