I have a 2006 Silverado LT 5.3L and just recently I'm getting problems with the 4 wheel drive.

Every time I start the truck the 4 Hi light is on leaving me to believe the 4 wheel drive isn't engaging and disengaging properly. If I put it in AUTO 4WD and then turn it off and start it back on it stays in AUTO 4WD. It also will not go into 4 Lo as the light blinks for about 15 seconds and then just stops or if it's in AUTO 4WD the light blinks and then stays lit on 4 Hi. I don't think it is in 4 wheel drive, but if I put it in neutral and then attempt to go into 4 Hi the truck will drive around with heavy vibrations especially while turning. I am not a type of person who goes mudding a lot, but recently I had to help a friend get unstuck in heavy mud so I believe that may have caused a problem, although it started to happen about 4 days after I got him unstuck.

Unimportant information, but I am only 18 years old and probably would not be able to afford taking it to a dealer to get it fixed. I do however work in a classic muscle/racecar shop so I have an availability of tools and staff to help me out, but they just don't know enough about 4 wheel drive to give me the proper help I need.