How you doing. Newb here i have a 2001 blazer i just bought a blzer 2 days ago. While driving at all speeds i hear a click, grind and loud hum from the front end that doesnt go away. I dont think its stuck in 4wd because the blazer burns out in 2wd. Its loud and annoying it only clicks under acceleration but hums when tires are movin. I need help fast i changed the wheel bearings yesterday and still the same. Thanks in advance for the help!

 

The front axle may be partially engaged. Check out the info in the thread linked to below:
4wd Front Axle Clicking When in 2HI - Goes Away when in 4HI/4LO

 

Also the truck has 140k miles on it and the cv boots arent ripped

One thing with that article I hear the noise in 4wd also its not just in 2wd.

 

That doesn't preclude the condition. Don't let the title fool you. The front axle engagement cable can be frozen in a partially engaged position resulting in the same condition. You need to check over everything that is mentioned just the same.

Also, please edit your posts rather than posting back to back. Rules are rules.

 

Sorry about that. This would cause a grinding and clunking noise?

 

Yessir, read through the theead and follow the procedure and it should lead you to the solution.

 

grinding hum dependent on speed.

 

Is it hard to take it all apart to check? Also any of these parts expensive?