I have a 99 tacoma prerunner and the drivetrain has just starting roaring and getting worse very quickly. It has 204,000 miles on it. Can anyone help???

Drive train noise is just one of those things that need to be diagnosed in person. Crawl on under there and check for loose u-joints, look for any leaks, give the pinion flange a good shake to check for play, and lube everything up.