on my 90 defender,i have noticed that on the end of the prop shaft connecting to the rear diff, on the actual universal joint some metal has sheered off and now the universal joint seems to be really loose how can i fix this,do i need a new part, i cannot see how to replace just the joint,do i need a whole new prop shaft????? i am only 17 and work as apprentice refrigeration engineer so am quite hands on but just not experienced in mechanics,can anybody help me, any information or advice would be very kindly accepted and very much appreciated, thanks guys,!!!!!