Would anyone know what size the BIG nut is that holds the rear pinion yoke on?? (1999 F350 Dually 2wd) I think its the bigger of the 2 rear ends because its a Dually I even tried my BIG 1 1/2" socket that I use on hitch ball nuts and IT is TOO small!! Does it take a special socket?? thin wall?? it doesn't look like it needs to be a deep well???? Thanks!!