Scudo 1.9 Diesel Problem

Hello all,new member here and in trouble, I am in the plant repair business and a friend came to me with his 2002 Scudo 1.9 diesel (140K) with a bad oil leak,to help him out I had a look and seen it was the front crank oil seal,got a new belt and oil seal for the Saturday morning attack,got everything off ok and then ran into the first trouble,with the crank sprocket removed to replace the seal I found that the guide washer that is rivited to the in-side of the sprocket had broken up and pushed the oil seal in,had to down tools when I got the old seal out and the new seal in till I got a new sprocket on the Monday,fitted it,checked that the belt guide had clearance between it and the oil seal retainer it had plenty,button everything up,job done,now 6K later the exact same thing has happened again,the guide washer fell out in pieces when I took the cover off,all the other sprockets are open either side and the idler pulleys are free,the only guide for the belt is the crank sprocket,has anyone else come across this problem,when I seen the first one broken I did not know if it was dropped or abused in some way that's why I went ahead but this time I will have to find the cause,he has been lucky (even though he don't think so) that the belt did not break,I will be checking the end float of the crank but if that's ok what could be wrong,open to any suggestions,thanks in advance.
Jim

I think you might get an answer in the SCUDO section

Ya I spotted that I had posted in the wrong section,but it was too late when I seen it,still same Citroen lump.
Jim