2003 Gmc Making "grinding Noise"

brandonp · May 18, 2010

Hi guys,

I have a 2003 GMC 1500 4X4. It is making a strange grinding noise that I can't pin point. It's most noticable at around 30mph under accelleration. There is no noise costing, always under accelleration or sometimes when braking. At 50mph and above the noise is a light hum. I have done my best to isolate the sound but am hoping that someone with a similar problem can help me through. It is not coming from anywhere up front because it makes the noise in 2 wheel drive with the back end on jack stands. It is making the noise in 2hi, 4hi, and in 4lo at the same speed (so it's not the transmission). I have checked the rear diff and it looks fine, no obvious chunks missing or anything like that, I removed the driveshaft to check u-joints and both move freely. So my question is, is it the t-case, or am I missing something. What in the t-case could cause these symptoms. Any help would be appreciated so thanks in advance.

Nytemare · May 18, 2010

Hi guys,

I have a 2003 GMC 1500 4X4. It is making a strange grinding noise that I can't pin point. It's most noticable at around 30mph under accelleration. There is no noise costing, always under accelleration or sometimes when braking. At 50mph and above the noise is a light hum. I have done my best to isolate the sound but am hoping that someone with a similar problem can help me through. It is not coming from anywhere up front because it makes the noise in 2 wheel drive with the back end on jack stands. It is making the noise in 2hi, 4hi, and in 4lo at the same speed (so it's not the transmission). I have checked the rear diff and it looks fine, no obvious chunks missing or anything like that, I removed the driveshaft to check u-joints and both move freely. So my question is, is it the t-case, or am I missing something. What in the t-case could cause these symptoms. Any help would be appreciated so thanks in advance.

I believe you may have the T-Case rubbing issue...I haven't paid too much attention to this issue as I have a 2wd, but it has something to do with a clip that goes inside and the pump wears through the T-Case.

Do a search on here for T-Case Rub and see if you can find out for sure if these are the symptoms.