Scirbe the relationship between the sheering box output shaft and the pitman arm. Use an impact wrench to remove the big nut. Use a pitman arm puller, looks like a small but very beefy pulley puller, to remove the pitman arm.

I've read replacing the the first seal you get to usually stops the leak.

Lots of debate on reusing the bolts that hold the steering box to the frame. Manual says to use new bolts, many say it's okay to clean the old bolts and apply blue Loktite.

Sixto
93 300SD