00 Silverado Input shaft question
 

Hey guys so I read the input shaft replacement writeup (which is a great writeup) but it doesn't mention why you would need to replace your input shaft. What are the typical symptoms of a bad input shaft?

My possible problems are that I have really loud clunk when going from drive to reverse or visa versa and I have a loud howling (sounds like rear ring gear is worn) coming from the drivetrain when cruising at highway speeds.

As far as I know its the original case with 280,000mi on it so it could be anything?

I just serviced the rear differential... Looks like I need a new set of gears. Its been rebuilt but apparently the ring and pinion gears were never replaced.

Thats my howling sound but still don't know what the clunk is. It sounds like its coming from the transfer case.

C'mon guys nobody has any advice?