Are you sure your prop is properly aligned - that's what killed mine.

The options I found are:
Use a 2nd hand donut

Get hold of the front section of the propshaft from an Escos or late Sapphire 4x4 and the output-shaft studs, and use the later thin donut

Make up an adapter for the propshaft to allow the use of the later donut.

I'm quite proud of mine and can get another made for £95 but you still need the donut (£60 or thereabouts)