on inspection around the back on of the drive shafts was not conected to the gear box. i know what your all thinking he forgot to tighten up the bolt when he re fitted the engine and box, when i finished the install i ran everything cheaking that everything was tight, i even went so far as to buy a net set of the lock washers. all the bolts were still located in the cv joint.managed to bolt up 5 of the bolts and go laning so it was not a lost day, the outher side were all tight but i managed to just crack them up a little to give me piece of mind.
i have just got in and droped the joint again and ran a tap through the thread on the output flange, and the bolt bit all good. its all bolted back up as it should be.
spot the last bolt to have come undone?

may be worth having a look at yours dont even want to think what would have happend if i were at speed and this happened!
neil