it ONLY does this when its in 4x4 hi/lo. i dont know if something is stripped worn out or what? it clicks every rotation the faster i go the faster it clicks? i dont think it does it all the time. sometimes when i put it back on 2wd it feels as if its still on & makes that click, the way i make it quit is by puting it in reverse & start reversing for about a foot or so then it quits? also if when im at an angle not too steep but not leveled & i put my truck in park & it just slips & keeps sliping unless i hold the brake or use the E brake does that mean its just the park gear that i have to replace? any idea? comments? advice? anyone?  

I am going to guess that you are talking about a 85 Blazer since that is in your id name.  You must have tha auto locking hubs.  To unlock those you need to back up after switching back to 2wd.  The clicking you are experiencing is worn out U-joints on the front axle.  Turn the wheels to one side and crawl below the truck and look at the u-joints on both sides.  To answere you question on the transmission ..... yes.  

thanks! i'll look at it when the sun comes up. yeah it is my 85 blazer (k5) people had told me that maybe it was a wheel bearing? i had thought that maybe it was something like gears in the hubs or something like that. i once kept driving with the clicking noise for mabye about 2-3 miles like that, is that real bad/serious? it doesnt make any weird/odd noises on 2wd?  

blue85blazer:
thanks! i'll look at it when the sun comes up. yeah it is my 85 blazer (k5) people had told me that maybe it was a wheel bearing? i had thought that maybe it was something like gears in the hubs or something like that. i once kept driving with the clicking noise for mabye about 2-3 miles like that, is that real bad/serious? it doesnt make any weird/odd noises on 2wd?

Driving with the hubs locked in on a part time 4wd  would be like driving with a full time 4wd; every thing on the front will be turning so not a big deal.  It just put more wear on the already worn out u-joints.  

thanks alot GM1tonOfFun! i rally apreciate your info.