grinding

I have a 99 Tahoe that started making a grinding noise when I start accelerating while in 2H. It is not coming from the transmission and sounds like it is in the 4WD transfer case. I can put the truck in 4Lo and 4Hi (although the 4 HI light doesn't actually come on but feels like its in 4H). In...

My vehicle is a 94 yukon SLE, 165000 miles, 4x4, 350. At 20mph i start to hear a grinding sound that sounds like its coming from the front of the truck. It goes away when i go below 20 and stop but starts again when i get past this speed. No idea what this could be. any helpful suggestions...

Hi and Thanks in Advance for any help or advice. I have a 2002 Tahoe LT (5.3Z-Flex Fuel) with 95,000 miles which has been having a few issues lately. 1) Cold Start (<45 degrees) Rough Idle and Code P0300. When starting the car in cold weather it first revs up to 2000-2500 rpms for a few...