1997 BMW Z3 Vibration upon acceleration, primarily low gear

Drive Train Axles Bearings problem
1997 BMW Z3 4 cyl Two Wheel Drive Manual

So I have the aforementioned vehicle and its making a pretty hard vibration when acceleratiing. I have an idea of the source, but Im not positive and just want to get some feedback, hopefully someone can reference some nice online material that I can review. The sound is a knocking like sound that seems to be originating about mid way underneath the car. I have not looked under the car, but suspect there is a drive axle coupling there and some part of that couplling is going out. I used to have a 1976 FIAT 131S and it was notorious for that issue and it pretty much sounds the same. So assuming Im on the right track, Id like some feedback on how tough a job it will be, maybe some things to check for to verify, the right scope of repair and parts replacement, expected cost and time frame and whatever else you think appropriate. Seeing a video online for the repair scope would be awesome. Thanks