The second location to be tapped is on top of the steering box on the raised rib shown here. A passage lies under this rib and is where fluid is passed from the front of the box back to the main part of the housing. The goal is to drill the hole in steps, then tap to access the center of this passage without drilling past the passage. To get the threads cut deep enough it may be necessary to use a bottoming tap or cut down a standard tap, as we have done in the past. Again, it is good to be mindful of metal shavings and thoroughly clean the inside of the housing before reassembly.