Not newbie.
2001 2-door Blazer 4 by 4 110K. I have not engaged the 4-wheel drive for about a year because I didn't need it. When I went to test it I found a vacuum leak - fixed it.
Tried the four-wheel drive and this is what happened: engaged immediately - heavy pull to the right - lots of rumbling noise from under the driver's seat - turning a wide corner (wide because the turning radius sucks) the front wheels squeal. Putting the vehicle in neutral it will slow down all the way to a stop very quickly.
Vehicle has never leaked except for the water pump I just replaced.
When I used the 4 wheel drive in the past it worked perfectly - no issues except for the turning radius which only sucked less than it does now.
Where do I start?