Looks like I have some work to do, but first need help diagnosing.

Last week heard I heard some relatively loud grinding and screeching in my 2005 Blazer, pretty sure it was coming from drivetrain since it did not vary when I revved the engine. Lasted about a minute then went away, has not reoccurred since.

I now notice some vibration when in 2wd, not severe but I can feel it. Only in 2wd, when I'm in 4wd it's gone.

So I'm thinking it's a transfer case issue and should probably search out a rebuild to install.

Any insight and info would be appreciated, thank you!

 

could be the u joints in the rear driveshaft. putting in 4wd is taking some stress of it

 

I actually replaced both rear U-Joints about 2 years ago. When those started to seize it was a gradual whining that I could tell was coming from the rear.

This grinding was much louder, sudden and then disappeared. I couldn't tell if it was coming from the front or rear so suspected the transmission or transfer case.