I have an 03 Silveraddo Duramax. The t case was toast when I
bought it. I had it rebuilt and thought all was fine. When I
went to shift in to 4HI while driving there was lots of
grinding/noise sounds like it is coming trom the T case. Spoke
to a couple of mechanics and they said maybe front diff actuator
was bad so bought a new one and installed it. Still the same
problem. When sittling still it all engages fine and no noises
at all even when going down the road. At low speed it will
engage but wth a loud "clunk" at speed only griding. When I have
it engaged and going down road can shift from 4HI to 2HI as long
as I dont "unload" the front end. Any ideas on what my problem
is?