4wd Problem?

[cmf21]

Last night I pull into the driveway and hear a noise coming from the front of the truck. Sounded like the 4wd was engaged. Didn't really think much of it since I was driving on a wet dirt road from a monsoon that had blown through. Thought I probably got something dirty up front and just needed to be cleaned. Ended up cleaning it and took it out this morning. Feels like it's still engaged. Lights on the dash still read 2wd but still sounded like it was engaged when turning. I also noticed my gas mileage had gone down some. I turned the dial on the dash to auto and I get this clunk feel when it engages. Never had that before.

 

What could be the problem??? Truck is a 07 nbs

[Rocco715]

You should know if your truck is in 4wd when turning on dry pavement. The tires will want to slip and the truck will jerk you around, try cycling through 4hi 4lo then 2wd going in straight lines then sometimes going in reverse will help disengage 4wd. That clunk feel when turning it to auto is the 4wd engaing.