Disco 2 front prop shaft universal joint

hi i have a 51 plate td5 with 140000 on the clock. the front prop shaft has 3 universal joints one of the rear 2 was nackered . i contacted my local independent land rover garage and tried to order the part. they said you can only get the front one as it doent show a part number for the rear 2. you will have to buy the prop shaft £290 + vat. my mechanic mate who was doing it said i wont have that the 3 uj s all look the same so we got the front one £23-60 he stripped it down and shure enough it fitted. only thing to be carefull of is when you take the old uj out there is a metal ball inside the prop shaft as you pull out the uj inside the metal ball is a spring also inside the ball there are loads of needle bearings a bit fiddley but saved me a lot of money. hope this might help any one in the same position.alan.