Ok another source to check is your universal joints on your drive shafts, Even if you just recently replaced them, I know I replaced mine two years ago and just recently before I sold my Blazer I was experiencing a Howl at variable highway speeds and it was also a vibration when slowing down and it turned out to be mine had seized right up.

 

I realize this is kind of old post but I have same problem on my 01 blazer ls zr2. It has the auto 4 button so there is no vacuum on the t case it comes from the manifold to a solenoid on the firewall then to the actuator. But I check it out it seems to be working properly but I still have the vibration under my feet and front driver side tire can wobble at speeds 30-60. And no it's not the tire (balanced and rotated them). Cv axles seem good and wheel hubs. I'm thinking what other guy said the cv on front drive shaft is bad. Having it checked tomorrow by a shop but anyone had a solution yet? I'll keep you updated tomorrow.

 

Did you ever find the cause of the noise?? Sounds just like the problem with my 2001... I'm refering to the post by Brians1bad72

 

Tagged for future reference..

 

Just bought a 98 2 door LS with the 3 button switch, the noise is not apparent until i reach 30 mph, the noise is described as a growling noise while coasting when i reach 45+mph the coast for a long period of time, i hear the noise slightly louder while accelerating but louder decelerating, but i think i saw smoke coming from under the vehicle at these speeds in the rear view mirror, the noise is in the front, the rear differential is full of new gear oil, my only guess is the transfer case chain is so stretched out it is rubbing the bottom of the casing. I tried switching the drive mode, but it does not matter if engaged or disengaged in 4 hi. Do you guys have any ideas what this might be?

 

anyone have any updates?

 

My first post. Old thread, same problem. I have a 2004 Blazer 4wd. Noise coming from passenger side front tire area in 2Hi. Noise goes away if I switch to 4hi. No issues with running in 4hi or 4low. No noise in 2hi accelerating uphill. Noise starts as soon as I take foot off the gas. Gets louder until I come to a complete stop.
All or most ABS components replaced. Hub assembly both sides replaced. Wheel speed sensors replaced. Replaced transfer case vacuum switch. I'm out of ideas. Local car repair shop says front differential but I don't trust them. Already spent $1800 on the above at this shop and still have the described noise. Any help or ideas would be greatly appreciated.

 

 

I'm getting ready to dive into something similar. Commenting so I'm subscribed. Will follow up with what I find.

The Blazer is new to me and I've only driven it on the test drive and home. Noise is speed dependent. Seems to start around 20mph and gets louder with speed until it levels about 55mph. Front end is a little floaty so I'll be checking hubs and ball joints and such. The rear pinion doesn't appear to have any play so I don't think that's it.

It's a 2001 with 4 button (NV236?). I'll be checking all the vacuum business as well...

 

My first post... I have a 98 Blazer, 4x4. I have a " rubbing kinda sound " coming from the front passenger tire area. The steering wheel does not pull, no play at all, let go of the wheel and she stays straight as can be. I have checked everything, nothing loose, broken ect, I am out of ideas here. Any thoughts or suggestions would be appreciated!