driveline play!!! loud clunk.

ok so heres my hypothesis, something in my transfer case has alot of play to it. Heres why I think that, I can grab my rear or front driveshafts and turn them a noticeable amount in either direction, like 60 degrees or more. also if im going about 10mph, and step on the gas to speed up it makes the most horrid clunk/clank/bang noise ive ever heard. So am I right and is it the transfer case? or is it something else? Just hopin one of you good souls can help me on this, my poor truck has 123k on it and its not gettin any younger.

I would definitely try replacing your U-joints first; they're cheap. I had the same problem on a 2wd silverado, and we swore it was the rear end. So, we replaced the rear end. Didn't help. We pulled the shaft out, and, sure enough, one of the u joints was really worn out. Changing that got rid of the clank, and the slip when it was put in gear.

What about the slip yoke deal? Replacing them with nickel plated ones.. Just an idea. I've got the problem and havn't gotten around to checking it out.

I have a 2004 ext cab and mine was clunking pretty bad I brought it to the dealer and they told me they revised the tsb that included MY truck they replaced the slip yolk and the clunk is now gone! I only have the 2nd to third clunk But they will never fix that. but the start stop clunk is gone So I would say it is you slip yolk you need the nickle plated one.