Help Solve the natorious clunking noise

[sebringjxi01]

I have a 96 tahoe. Keep up on all the maintnence for the time i have owned it as well has the original owner. When i shift from drive to reverse, the infamous clunking noise happens. I can drive all day in drive and the problem will never make the noise, but when i go from reverse to drive or vise versa, i hear the annoying clunk. It is 4 wheel drive and some of the other threads say that the problem is fixable but it doesn't say HOW!!!

I am no expert under my truck, but i can hold my own. Can someone just tell me what i need to replace and give me the general idea as to how to do it.

Thanks to all responses. I love my tahoe and i would hate to have to stop using reverse, but this is driving me nuts!!!