hi just changed rear diff and there is a oil leak where the drive shaft connects to the diff any ideas what i did wrong

colin, May 2009

my 2004 transit 125 t280 has an oil leak which is proving difficult to find.what is the most probable cause gentlemen?it drips from the bell housing,but it gets blown all over the underneath of the van.i was thinking rear c/shaft seal or oil cooler.thanks in advance

john, April 2010