Is it possible to 'spring' a transfer case? I was heading out of town
on ran into black ice as the freeway started up hill. There was quite
a bit of traffic and I started to fishtail on the Interstate at about
35 MPH. I didn't check the speedometer but guess I was around 30 MPG
when I pressed the 4H on my 1997 GMC Suburban to engage the four wheel
drive and heard a fairly loud CLANK.

So far everything is, and has been working fine, but for some reason
at around 50 MPH, I hear a kind of loud whining that either sounds
like tire noise OR my transfer case. I wonder about this 'sprung'
transfer case thing because years ago, a friend had an old Ford 4x4
pickup that howled pretty badly at highway speeds and he told me that
he had 'sprung' his transfer case (never said how he did it, though
his would have been of the year where you had to be at a complete
stop).

I was under the impression that with the push button to engage 4x4 GM
products, a person could be rolling down the road at 30 MPH (or so)
and be okay doing this. I guess in retrospect, I'm still glad I did
it because I think it kept me out of a winter nights freeway collision
but am a little concerned about the howling sound (again, kind of a
loud road noise sound).

Anyone else experienced this or have ideas?

thanks,
John