My 2000 blazer lt it seems that when you try to drive it trys to go into 4x4 part way it squeals and makes ticking noise it also feels like the brakes are on any idea what is causing this

99 Blazer driving hum,noise - Blazer Forum - Chevy Blazer Forums

blazerforum.com > ... > Steering, Suspension & Drivetrain
Dec 31, 2007 - 99 Blazer 4x4 has constant noise-humming that occurs non-stop and increases and ... Sounds like it is coming from rearend but not 100% sure. 99 LT 4x4 Rear End Whine
Nov 5, 2013
7-5/8 or 8.5" ring gear?
Jan 16, 2012
99 Jimmy 4x4 humming noise
Dec 24, 2009
More results from blazerforum.com

Is the clicking noise most prevalent when turning close to full lock?
If so, then check your front drive shafts. It could be that their joints are heavily worn.

If not, then please describe when the clicking noise is most prevalent.

could be a bad pinion bearing or something of that nature
our truck had the same thing happen,it only did it in 2 wheel drive not 4x4.....it was the transfer case

does it get louder above 45-60mph? and much quieter at low speeds. It could be wheel bearings, a rear differential or front differential. If its a grinding humming noise its wheel bearings, listenin to see if theyre coming from the front or rear, left or right, or both when your driving to know what wheel bearing are bad. If its a whinning noise, its probably a differential. check and listen to hear if its coming from the front or rear. Also, check for loose plastic around the wheels. Lastly check your tires for uneven or choppy wear. move your hands front to back on the top of the tire. does it feel really choppy and rough, maybe you just need new tires

Have someone sit inside and turn key on, the fuel pump in the fuel tank should make a humming noise for a few seconds then shut off (primes the fuel system) until you start cranking.

time to add some oil

they likely used 10/30

add a litre of 80w90 it will thicken the curent oil and should stop the noise

it is likely you will need thiswith all your future oil changes high nilage motors make noise and require thicker lubrication

I would start with a belt. While removing it feel how much tension the tensioner has on it, on the 3800 egnine they have a stiff tensioner(sorry I don't have any specs for how much) After you get the belt off you can look at all of the pulleys and spin them to see if the bind or look for stuff stuck in the grooves on the pulleys.
It sounds to me like the belt is streched. I would not recommend one of those gator back belts, they seem to make more noise sooner than a good v notch belt. But thats just my opinion!

there could be several reasons for the ticking noises. to be sure can you tell me everything in detail from when you start the vehle to when you shut it off. this will help me narrow down the likely cause

Check the fluid level in the trans. With the engine hot, truck idling in park, make sure the fluid reaches the "HOT" range on the trans dip stick and it is bright red and doesn't smell burnt.

the trailblazers are designed to shift from 2 wheel to AWD on the fly. BUT NOT TO EITHER OF THE 4 WHEEL OPTIONS. I'd suggest you get it to a mechanic to evaluate the damages.
Jer