Loren Posted March 19 Report Share Posted March 19 20 hours ago, D35 Torpedo said: I don't understand how a worn worm would cause binding, only play. The wear on the worm and roller is minuscule compared to that of the roller and pin. These are slow moving parts. Even without oil, they can go without wear for a very long time. The roller and pin get hammered out from road impacts like potholes. Once the roller has slop, the sector can freely move. In the center, both gears are square to each others. The roller is loaded evenly against the pin. At this point only end play can be exploited. But at either end the roller isn't loaded evenly. It has less tooth engagement and forces are vectored. Now end play has a greater effect and pin slop is now a factor. Hence, greater play off of center. There is zero adjustment to be made on the worm. Just shim the bearings to zero lash. All the adjustment is in the sector screw. The same forces that hammer the roller and pin take out the bearings over time. Anyway, that's my full analysis based on my findings and experience. Okay lets try to state this another way. A worm gear is essentially a thread. In a steering gear that thread is curved to the radius of the sector’s movement. The roller on the sector is not really a nut or even a half nut. It basically contacts the worm with one of its three teeth on a very limited area when everything is perfect. Start getting wear or damage and the other two teeth start getting involved. Only its more complicated than that because of helix angle of the sector. One of the out board teeth will be over center and the other will be under center. Add to that those outboard teeth are in contact with the adjacent teeth on the worm and because the center tooth is worn ( or in contact with a worn worm tooth ) it is putting them out of position. Someone wanting to adjust out the wear will screw down the sector adjustment and that makes the whole thing worse. Bottomline: The way to fix it is a new set of worm, sector roller, bushings and bearings. Quote Link to comment Share on other sites More sharing options...
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