My 2004 Yukon XL has a grinding noise in the front end…it only happens when i push on the gas, when i put it in N the engine sound fine so i know that its not that, but when i put it back into gear the grinding starts… when pressure is pressed to the pedal so im at a loss and am all out of ideas on what it could be…it has an option of traction control and when turned off and on it makes no difference…HELP ME PLEASE…DAVE