2002 Z71 transmission clunk & braking problem

I'm new to this forum. I have a 2002 Z71 Silverado, real low miles, with the transmission clunk from 1st to 2nd that others seem to have also based on my research. In addition I also have the loud clunk in the area of the transfer case when shifting into reverse. I've also taken the truck in twice and gotten the standard answer, yes their is excessive play in the transfer case but it's within normal standards. The second time they did the grease on the driveshaft spline (bulletin fix) and that made no difference. In addition, I've recently noticed that when I slowly start to accelerate then brake, it feels like the entire suspension moves back and forth. I can feel it in the steering wheel also and hear it towards the rear end. It only happens at real slow speeds and not all the time. You can really notice it if you give it a little gas then brake.

Anyone heard any more news on the clunk problem? Also, anyone experiencing a similar braking problem?

Other forums I've read have said that some dealerships have replaced the tranny fluid with thicker tranny fluid and that helped the problem. Anyone had this experience? I thought ATM fluid is pretty standard.

the bullitin fix with the grease was a early one, there is one that says to have the front yolk replaced with a new nickel plated one, mine had the clunk or squak sound when stopping or pulling away but the grease fixed it somewhat but I still get it sometimes but I know there is another bullitin to change front yolk for a perm fix