knocking fron underneath floorpan

[steveblock1971]

I am the proud owner of a 2000 v plate 76ps SWB 80 van,i have followed lots of advice on this site since i have owned this van and i can honestly say it has never let me down.A few months ago whilst i was fitting a new full exhaust system i happened to grab hold of the prop and give it a bit of a twist in each direction,from somewhere inside the chunkier rear section of prop it made what i can only describe as a "ringing" sound like striking a small bell,there also seemed to be some play somewhere but it didn't appear to be from the diff end,more towards the middle nearer the centre bearing.
In more recent times i have noticed that whilst driving the van especially over bumpy roads and always when the engine is on the overrun when slowing you can hear a knocking sound which i first thought was my new exhaust banging on the bottom of the van,but i have checked and there is plenty of clearance.Also there seems to be a lot more "snatch "when taking up drive.
I have checked on my TIS and there is a small section near the centre bearing that is splined together,there is also a TSB about knocking noises but it implies that the centre bearing torque is wrong.
My question is, does this splined section suffer from excessive wear, as this van has never done any real work,and if not what else would cause this type of noise?
The van has covered 118,000 miles and i have done all the normal transit jobs such as ball joints and replaced broken droplinks,many thanks

steveblock

[MinorMatt]

what condition is the center bearing rubber in?

[steveblock1971]

as far as i can tell it looked ok but that dosen't mean a lot if its perished internally

[MinorMatt]

ok, grab the propshaft right next to the bearing and shake it! If the rubber is knackered it should be fairly apparent!