Roar from Right Front

[Emmitt101]

I have a 96 LT with 84,000 miles. Not long ago I heard a loud nise from right front and was told it was the wheel bearing. As you all know, being 4WD I had to buy the whole hub, not a major problem. Pretty easy to replace. Now the sound is back and it seems the only way to stop it is to pull over, switch to 4WD, move forward a bit and then go back to 2WD. Could this be a vacuum problem because it seems to happen about every time I move the heater controls on the dash. Checked the ball under the hood and the lines look fine. Other than leaving the controls alone what should I look for? Any Advice would be GREATLY APPRECIATED!!!!!!!!!!!!!!!

[wirenut699]

Could very well be vacuum related.

Search this forum for "vacuum switch" or "4WD vaccuum". There are a few threads that go into it.

[BlazerLT]

Sounds like the 4x4 is acuating when it shouldn't.

It goes completely away when you switch the 4x4 back and forth?

Also, what brand of hub did you install?

[muddog321]

As a test pull the main vac line that goes down to the vac switch on the top of the xfer case and plug it (golf T works well)ff under hood - does that fix it? If yes you have a problem there. If no, look at other items like CV axles and sorry, a process of searching and listening. Blazers have looks of parts that act up with age and can make noise.

[Emmitt101]

I don't really remember what brand, but yes it goes away when I switch back and forth until the next time the dash controls for the heat are adjusted. Really aggravating at times.

[laxman21]

Start the truck and ljack up the front right and see if you can spin the tire. If you can't it's in 4x4 all the time.

I had this problem because the switch on the transfer case failed in the open position.

[BlazerLT]

Originally Posted by laxman21

Start the truck and ljack up the front right and see if you can spin the tire. If you can't it's in 4x4 all the time.

I had this problem because the switch on the transfer case failed in the open position.

Good idea.