05 transfer case clicking

hey guys new to the site ,since my blazer is out of warranty i guess i'll be using this site quite often. ha ha. my problem is with the transfer case ,in 2 wheel its not a problem but as soon as i engage into 4 wheel there is a clicking sound coming from the case. its a 2005 with auto trac,4.3 with only 80,000 km. if anyone out there could help me out ,it would mean a lot. thanks in advance. by the way i just changed the case oil today and it didnt help.

Welcome to AF.
Does it lock into 4W drive good?
Any more noise when turning or going straight ahead?
Does the noise speed up with MPH?
Take a look at the front drive shaft and axle joints.
Is the front end greese level ok?
MT

Welcome to AF.
Does it lock into 4W drive good?
Any more noise when turning or going straight ahead?
Does the noise speed up with MPH?
Take a look at the front drive shaft and axle joints.
Is the front end greese level ok?
MT

thanks for the the ideas , it does lock in good,no other noises when turning,and it does speed up a bit , talking to another blazer owner this am. and he mentioned about having 2 sensors on the case, maybe 1 of them is pooched ,im going to do some more research

You are welcome.
But i would check the joints first.
MT