2001 will not come out of 4wd without kliking in front drive shaft

 

welcome...you have 1 or more of the following:
different size tires front to rear,
a flat tire or very underinflated tire,
2 new tires and 2 very worn tires (effectively the same as 2 different sized tires)
front differential gearset is a different ratio then the rear
the front axle actuator cable is "hanging up" or sticking
the vacuum switch on the top of the t-case is sticking.

Those are the ONLY things that I have seen or can think of that can cause this condition.
Let me know what you find or determine please.

 

when my 2001 blazer is in 2wd my front drive shaft kliks and speeds up as the truck speeds up. it does not klik in 4wd.also, if i turn the front drive shaft by hand it makes the kliking sound (in 2wd) ps how far should i drive in 4hi

 

Sounds like the cable is not pulling the actuator arm back far enough away from the axle might be the vacuum actuator under battery may be failing...