Here's a picture. "Sand..." misspoke, the locknut is at the back of the box, by the hose. Make sure that you have a wrench on the box(forward flats) when turning the locknut(clockwise looking aft) so that he hose doesn't turn. After it is unlocked turn the "box" half a turn and check with engine running, then another half, etc. Remember to lock it up. You can change the packing in the water if that doesn't work for you. Tighten the hose clamps while you are in there too.
P.S. that hose should have four clamps, not two.