Those are Saginaw recirculating ball nut style. The procedure for reversing would be the same as reversing a Vega or Corvair box. You have to dis***emble the entire box and re***emble with the steering shaft exiting thru the opposite (bottom) end of the case.This involves removing the ball nut from the worm shaft (removing all the balls) and reversing It on the worm (reloading the balls) shaft then reinserting into the case. You might have to drill a hole in the bottom end of the case for the shaft to exit-or there might be a plug you can knock out. You'll need to plug the existing hole in the big threaded plug because it's going to be on the bottom.
thanx dale....thats wut i was thinkin do you now if theres a preload on that when it goes back together
Once back together, the worm shaft is trapped between two ball bearings-one in the case and one in the big threaded plug. Tighten the big plug until you have light drag on the shaft. You don't want ANY end play. The gear lash is adjusted via the screw in the sector shaft cover. That's adjusted only with gear centered and no load on the mechanism. (Ideally in the car, wheels straight ahead, drag link disconnected and gear centered-you might have to adjust drag link length to insure everything matches up when wheels and steering gear are both centered.)
The Jalopy Journal
