Yes, Jim Carter sells the replacement worm gear shaft and roller ball pieces, with that and a decent sector gear, you should be able to make a good working unit. Bearings are also available. Don't limit yourself to '46, any of the '41-'46 boxes will work, from 1/2 ton up to 5 ton, the COE is different. The shaft length is different on the bigger trucks, but sectioning the shaft is easy enough. The gear boxes are all the same size. "41 is the same design but the internals will not swap due to the roller ball diameter. "42 - '46 are the same. I have a '41 gear box with the shaft cut and a '37 top section welded on. This gives me a better designed, easier steering box with the look and fit of a stock '37. I used a worm shaft from a 5 ton truck with low mileage. Don't worry about welding on the shafts, any decent welder can make a strong joint. The worm gears are pressed and brazed to the shafts from the factory, so it's two piece from the get go.
