thanks for the reply i popped the shaft into my gearbox guy this morning and he confirmed it is the whole output shaft that needs to be replace.
he said that any bc box output shaft with the same number of teeth should be the same it has 15 teeth,well supposed to lol.

i do have 2 s2 boxes but as the crown wheel is different i very much doubt they will be the same. im not very confident in ordering a shaft from a random site, simply because it it lets go and takes the box out completely ill struggle to get another one
i also can get my hands on an rs1800i box for a very good price which has the same mounts without lsd but i need to do more reading


Thanks again tony