Can anybody help me out?? I have a 2004 blazer and as i was getting off the expressway, I heard a very loud whining noise coming from the right front side... When i put it in 4 hi it goes away.... Any suggestions??? I checked the vacuum hoses from the transfer case and they seem to be connected ... Maybe the switch????

 

I have a simillar noise I am trying to diagnos. If I come up with anything I will put it up.

 

Same here. It's like a whining noise almost like a hub bearing or u joint but it is non existent in 4 high. And it's only at higher speeds that you hear/feel it

 

Does it go away when you turn your wheels right or left?

 

Mine doesn't

 

it goes away when you put it in 4 wheel drive... i worked on it all weekend trying to figure it out... i chased down vacuum lines coming off the transfer case... i did everything short of tearing the differential apart and changing the switch on the transfer case... i had an abs light flash on and off then took it for a ride and the sound is gone... i have no idea what it is..

 

Sounds like you have a faulty transfer case vacuum switch. Is this a 3 button 4wd unit ?

 

the switch?? figures... i was gonna change it but some of my firends were telling me that the switch wasn't the problem.... i will check into that... thx

 

I wasn't referring to the switch on the dash. This switch is on the top of the transfer case above where the front driveshaft is. It has 3 vacuum lines that attach to it. This is assuming that your blazer has a 3 button 4wd set up.

 

How hard is it to change that vacuum switch. Any tips and tricks would be appreciated. It looks pretty hard to get at