[iagardner]

Thanks for the reply!!

The only grinding going into 4Lo was due to my impatience in not waiting for things to slow down before trying it. But it did seem to move properly and "engage" 4Lo.

Yes, the indicators are operating properly and light up as expected which is why I assumed things were working.

My Son has the Blazer right now (we bought it for him to drive to/from school/work) but I'll check out the remainder of the areas you've outlined. My feeling is that it's probably a switch or vacuum line. We've just replaced the rear u-joints and I seem to recall checking the front ones and the drive shaft didn't turn...but I'll check it again.

Thanks again for your response and I'll definitely post what I find out!