Hey guys, I 'm hoping someone can help me out here. I jacked up the front end of my 98 1500 to change out my front drivers side tire. After I was done I started hearing a loud knocking noise coming from under the truck. It sounds similar to a flat tire sound. Seems to be coming from the rear, but I can kinda feel it in the front. It seems to knock when it's at 1000-2000 RPM. Espeacially when I lay off the gas. It's definitely a sound that goes along with the spinning of the tires. I'm thinking it's maybe a problem with the drive shaft but I'm not sure, I'm not really to knowledgable about cars. Any help would be much appreciated.
Well guess I shoulda added that I had a new brake line put in a few days before. And I noticed that it only seems to knock hard when I pull off the gas pedal. I took it to a Firestone(complete car care) to have the new brake line put in and I took it back in after the knocking started. I don't know if they didn't drive the truck around, but they said it was probably that I needed new tires. Now I bought this truck in Sept. 2010 with the same tires that are on there now and its never made this sound before. One more thing, someone told me that if the tires are unbalanced that I would get some noise. Forgive my ignorance....but how would I no if they were unbalanced?