Well, I'm pretty sure its not packed with mud, as I rarely go offroad....this is my daily driver haha.
However, I DO have a 6 inch lift, aftermarket wheels, 35 inch tires, AND wheel spacers. I'm thinking this combo might void my warranty?? If I do take it in.....I will take the wheel spacers off beforehand.
I have mud tires (Firestones)....and this noise started shortly after I had them rotated (this is the first rotation for them). I'm thinking I could have a cupped tire? Guy at tire shop said tires could be "stepping" (thats when you run your hand over your tire and it feels smooth in one direction...but feels "choppy" when you rub it the other direction. I did this, and they are indeed stepping. He said to drive on them for 1,000 miles and it should go away after the tires wear a bit more.
I had both my front and rear differentials along with my driveshaft checked.....they all look fine.
I think it might be the tires........(or a wheel bearing, haha)
