I just replaced my clutch on my 46 1/2 ton, I had to unbolt the front shackle bolts on my rear springs and unbolt the ujoint in the front of the tube and it will slide back about 3 inches, enough to move it out of the way,then you can get to the clutch and pressure plate from underneath

http://i629.photobucket.com/albums/uu14/kurtdh519/002-1.jpg