I have been following the page on the dieselstop.com (ball joint replacement), to help me replace the passenger side main seal on the front axle of my 200 F250 SD V10 6.8L. I followed it word for word. However on reaching the end of the job I find the axle on that side is very difficult to rotate, I can barely turn it at all by hand. Rotating the drive shaft by hand causes the divers side axle to turn quite freely but the passenger side stays still (I have the stock diff). Any thoughts ?

(I took the axle to my local Ford on Saturday to fit the new seal and the nice man fitted it for free. He even said I could have just borrowed the tool, taken it home and done it myself if I had wanted. Great guys !)