UJs or gearbox or even something else?

Dear forumites

My 'trusty'????? old 300TDI has developed a strange resonant vibration when accelerating through 3rd, 4th & 5th gears starting at around 1800 rpm and gets steadily louder as speed increases.
I've been underneath and can see nothing rubbing or loose. the UJ's appear to be ok after grabbing the shaft and giving it a good twist and shake (ooer missus)
Is there any way I could check to see if it is gearbox/ transfer box related?

is the vibe still there above 1800rpm with no load on ? eg at a set speed but not accelerating just holding the speed .

Sorry I'm late getting back to you Bell Autos.

I've looked around the rear diff/ prop shaft and have noticed that at the cush drive rubber the diff/ prop shaft interface connecting bolts have torn through the rubber to such an extent that the bolt heads securing the assembly have fouled against the prop shaft, wearing part of it away; but only in the reverse direction not in forward. Could this be responsible for the noise and also the rear wheels locking when slowly reversing in gear but with the clutch depressed?

thanks ERR4419blues.

It does sound a bit suspect may be you better get it changed just incase

Just in case it was the diff I bought an axle assembly from my local scrappie after assurances that the one they were selling would definitely fit. Guess what, when I got home that the diffs are different. Last time I believe a scrap dealer!

I just took my 300tdi to Foleys in Roydon for a cambelt change (£180: excellent bunch of Guys -very helpful: even had a set of LHD headlights for £20)

There is a rumble on mine at around 50-65mph which I thought was a UJ or prop etc. Having fully checked all links they could find nothing specific, and after a test drive put it down to typical landrover "character". However, they did mention another customer who had a similar problem, and, although nothing was apparently obvious, they changed a prop and the noise went.
Point being, sometimes these old tubs seem to grumble away with various noises, most of which may not be catastrophic, but without changing all UJs Bushes props etc. you may never discover the source.

Valid point Vent De Grenouille but I am selling the old girl so I can buy a swb 2A for some conscience free off roading so it needs to be in decent order. If anyone is looking for a 1996 300 TDI ES with 150k on the clock ion good nick except for that damn noise (I suspect diff pinion bearings)then this one is up for sale.

Found the problem! I changed the rubber doughnut on the prop shaft and hey presto everything is hunky dory. I took the diff off while I was at it just to check it over and it appears fine. Thanks for the suggestions chaps, Happy days!