I would check for free play in the rear transmission bushing at the same time if you are going to drop the driveshaft and replace u joints. Mine have always been quite worn and have alot of play by the time I did u joints.

Thanks for the input.

You can check for play in the driveshaft's u-joints by pressing firmly on the brakes and shifting back and forth from Drive to Reverse or just letting out the clutch a little (haven't done this myself).
If there is a noticeable, consistent THUNK or squeak, that indicates play in the U-joints.

You can also squirt oil or grease into (inside the seal) the driveshaft support bearing - if that quiets it down, that confirms the driveshaft support bearing is bad.

The support bearing does wear out, and if you replace it, you should replace ALL of the u-joints. Bad u-joints can wear out the DSB and a bad DSB ... well, maybe it can affect the u-joints, but mostly it's just annoying. It will eventually seize up, like any set of bearings, so you should replace them.

Good Luck!

Center support bearing or a u-joint most of the time...if there is no whistling sound, it is likely a u-joint.