ok blazer gurus.....I need some tech help. Bought my 2002 4x4 blazer last year, changed out all of the emission sensors except O2 sensors when I first got it ( check engine light was on)......blazer ran perfect for the longest up 'til about a month ago. While driving on the interstate I started to hear a roaring/grinding sound, that increased with road speed and not the shifting of the tranny, coming from underneath. I pulled over to see if anything had broken but could not see anything. Began driving again and the noise returned. It sounds as if its in the rear end but could not tell. I had a guy look at it and he could not tell either where it could be coming from. Can my rear end be shot or can it be the front end stuff. i.e. t-case, cv,etc.....any insight would be greatly appreciated. I love my blazer but I would sell it if becomes too costly to fix.

 

Sounds like your bearings might be going out or maybe something brake related....

 

O yea...wheel bearings and brakes were the first to be done... forgot to add that.

 

I know in some cases unbalanced drive shafts, rear ends, and tires can have that effect, somethin else to ponder upon, is the noise consistent at frequency of speed, do you feel vibration? can you tell if its a side to side vibration or a up and down if vibration is noticeable assuming your tires are in good shape.