Hello everyone,

So glad to have found this web site because I have two Blazers that I am trying to keep on the road. Anyways my main problem right now is on my 2001 Blazer. This is a 2wd that has developed a serious noise when going around 30 to 50 MPH and it can be felt in the floor of the vehicle. I tried putting the tranny in low gear and when the noise began I checked speed and RPM. When I let the tranny go up a gear the RPMs drop naturally but I maintained a 40 MPH speed and the noise did not change one bit. This was the case when I let the tranny go up yet another gear. From this I am going with the noise and vibration being in either the drive shaft or rear end.

Anyone have this happen before and if so what was it? or does anyone know what this is?

oh BTW, this noise and vibration does continue at higher speeds but it is less noticable.

 

not positive which setup you have, but I have a '98 S-10 that had an ALUMINUM driveshaft in it....
Yes I said Aluminum
in a pickup......
I know.....


Anyways. I took it to my Machine shop guys after going through some U-Joints... found I had actually twisted my driveshaft a little and put it out of balance.
I am told that the torque from the 4.3s is actually enough to put a light twist in em...
you may have also smacked your shaft
I Suggest you check U-joints and then if your driveshaft is a nice grey color(Aluminum), possibly having the shaft rebalanced or replaced

 

I too would suggest you check the u-joints in the driveshaft. They will typically start to chirp/squeak before going completely bad, but shock loads, etc can cause sudden failures.

If the driveshaft looks good and the u-joints are ok, then it is possible that you have a bad wheel bearing or bearing inside the rear diff. You could service the rear axle to have a look at the condition of the gear lube to see if there is evidence of a problem inside the diff.

 

Well I had the idea that it was from the drive shaft or the U-joint due to a diagnostic tip from a book I have but in the end the book was wrong. While driving the Blazer over the Christmas Holiday I noticed that when I went into a hard right turn (yes I like to push my Blazer to the edge) there was a thumping feeling in the steering wheel. It only happened when I turned right at high enough speeds to really push the hub bearings. When I got back home I jacked up the driver side of the vehicle and what do you know, the wheel does not turn freely. All that noise and stuff was being caused by the front driver side wheel bearing assembly.
Yep, "assembly"! Can't just put a new set of bearings in it for a decent price. Have to replace a whole assembly for over $200.00!
OK this is case and point. Old Trucks RULE! No Computers, no Assembled Parts, and No massive confusion of wires and hoses to figure out, just a simple machine with no extra junk attached.
One more $200 part and this 2001 Blazer may go out front with a for sale sign on it.

 

You just said in your post that you like to "push" and "beat up" your vehicle, Then your gonna sit there and complain about putting money in to it when it breaks...