I have been hearing a grinding sound in my front end lately on the 1-2 shift in 4wd. Then tonight I was doing some tuning and while I was stalling up the turbo in 4wd I heard a grind and pop in the front end without moving so I let off and came home. I couldn't see anything wrong so I took it back out and hit the 1-2 shift in boost and I heard a grind and pop but it stopped very quickly and drove fine. What could this be? It doesn't have any problems in 2wd only in 4wd.

 

Anybody got any ideas? I'm supposed to be racing on Sunday and I don't know if I should now.

 

sounds like a carrier bearing to me,I wouldn't push it in 4wd until you get it checked out.
i would pull the plug on the diff and drain the oil to see if there is any metal in it.Evan if there isnt I wouldnt push it just because that isnt the strongest frontend on a good day and if its making noise and you break it at the track you will go home behind a wrecker.IMHO

 

Any clue on how much it would cost to replace the carrier bearing? Sounds expensive.