This morning I was driving to work and all of the sudden my 2004, 2-door started to behave weird/badly. I was in 4x4 going around 45 and I let off the accelerator and the truck surged and made a clunking noise. It did it three or four more times then I quickly pushed 2WD to see if that would fix it. Well it did. I am worried about the 4x4 now. I got closer to work and I checked the 4x4 again. When I put it in in clunked HARD when I accelerated lightly and I decided it had enough and I put it back into 2WD when it made another HARD clunk.
I checked the best I could under the vehicle to look for bad CVs, U's and whatever else that might look out of place/broken but I couldnt find anything. I dont know where to start!!
Doesnt help that its -7 outside right now either...
Another side note:
Now I am wondering if I did everything I could have to maintain the 4x4. Seems like I didnt. I think I did but any insight would help.

 

The hard "clunk" was most likely your transfer case motor having difficulty moving the gears between hi and low. Is this the first time this has happened? How often do you use your 4 hi? Do you shift on the fly a lot?

 

I do shift on the fly a lot. I never do it under power though. I have used 4 HI quite a bit this winter. Its been a bit snowy here in Michigan. My blazer is a manual and I either push in the clutch or make sure the vehicle is definitively coasting (not in compression or under power). I took it to the dealership today and they said it was a problem with the transfer case as well. Well, that doesnt tell me much. I wondered why it would just go out so randomly while driving under normal conditions and Iwant to knowwhat is exactly wrong with it. What part of the transfer case is bad?

Is this an easy evaluation to do myself? I want to rip it off and figure out what is wrong.
They said it could cost mearound 1300 to fix it....yikes.

Thanks for your thoughts and help!