stuck in 4 wheel drive low

[quote:e95491a3e3="nikpen1313"]Drive Train Axles Bearings problem
2002 Chevy Blazer 6 cyl Four Wheel Drive Automatic 112000 miles
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My Blazer seems to be stuck in 4 wheel drive even though it says it's in 2 wheel drive. I will be driving and then it starts making this very loud noise. I can get it to stop by pushing the 4 wheel drive button. I will switch it back into 2 wheel drive but it seems to just be a temporary fix. It happens very often when I am going uphill. I think it is now stuck in 4 wheel drive because it is very stiff to turn. I apologize if this sounds stupid or doesn't make much sense. I am a female that is trying to get this figured out. What could be the cause and how costly could this be?[/quote:e95491a3e3]

Can you describe the noise... is it a squeal, grinding, clunking, etc.

Ok one way to check and see if it is actually in 4 wheel drive would be too jack the vehicle up getting all 4 wheels off the ground. Make sure vehicle is Stable and won't fall. then start vehicle and put in gear. If all 4 wheels turn and your selector is set for 2 wheel drive then you are stuck in 4x4.

The likely problem is the vacuum switch has a leak in it and when the vacuum rises it activates the front axle interlock. When you shift it the valve gets moved and the vacuum bleeds off and then the problem starts over.

Pull the vacuum line off of the actuator (under the battery) Or follow it up to the nearest connection and disconnect it. Plug the line on the engine side so no vacuum can get to the actuator. See if it still does it.

The actual valve is about 20 dollars and isn't real hard to change.

the switch is on the transfer case