2003 blazer ls. okay so I need some advice. I'm having problems with my 4x4 not wanting to disengage completely back to 2 hi. The transfer case clicks over, push button switch says 2hi, the computer thinks its in 2wd, and it drives like normal. But I believe the front axle is not completely disengaging. It's makes a very loud whining and grinding noise from the front end but if you click the 4hi push button it instantly goes away.. It does not make this noise all the time! As of now just once every few days(blazer always in 2hi) I managed to drive it for a week (around 300 miles) no problem then boom, the sound is back. I've replaced the transfer-case vacuum switch, front axle switch, actuator cable, actuator itself, and both differential and transfer case fluid changed. No help getting rid if this intermittent noise. I noticed today the metal top on the actuator under the rubber has bent to almost a 90 degree angle. So replaced that again. I'm wondering if the front end isn't unlocking and there is so much vacuum pressure attempting it that it has caused a new actuator to bend? Just looking for some answers from someone who has experienced this problem or can trouble shoot it so I can keep my sanity. Thanks!