drivetrain . general fault finding process
 

hi guys, this is for my classic. I was driving along the other day then a knocking came from knowhere so ive had to take it off the road. Here are the symptoms.

it sounds like as if a wheel is loose.
the noise come as soon as you roll, loudest under throttle, still loud when decelerating, pretty silent if you balance throttle so there's no load at all.
still the same when you clutch in, and all gears are fine etc.
it is rythmic and is relative to wheel speed not engine rev etc, so just gets louder and quicker the faster you go.
the noise is very loud. Slight vibration present which wasn't there before, not felt through steering wheel though and doesn't change when cornering so pretty confident its not front end related.

now i have been searching about the internet and had a look under the car.
in leaning towards thinking maybe a prop shaft faliure, rear drive shaft faliure or heaven forbid the diff lol. Is there anything i can do to check the health of watch whilst its on my drive. Want to try and sort it myself before i take it to a garage and spend a load to just see what's wrong with it. A step by step would be great. Many thanks, Aaron.

Bump, any ideas?