Ok, I got a 99 durango box to swap out my old box with. I searched the internet all over and got all the "information" about the upgrade. Here are the Facts.. a 99 durango box(non plow) input shaft only turns approx 2.75 times. While the output shaft will only turn less than 45 degrees. 89 XJ stock box input shaft turns approx 3.5 times, and output shafts turns closer to 45 degrees. So this is why people want to modify the durango box to gain more output shaft turning to match the stock output shaft turning capabilities. I went ahead and spent my day modifying this durango box so I can have full turning capabilities as my stock box would have. The mods I did were remove the spacer that the worm shaft rides on in side the bottom of input shaft cylinder of the gear box. Also grinded down the tabs off the aluminum front cap of the gear box which would allow the piston to travel slightly further. And boy did I have fun getting this thing back together.. while originally following a write up on naxja.org, someone wrote to put the balls back in the piston prior to installing the piston into the gear box housing using some roll up paper method. This did not work. You must pull the output shaft and install the balls after the worm gear and input shaft assembly has been installed back in. This was no problem at all to do. Thanks a write up I found on pirate4x4.com with this information on how to rebuild a box.
So after all is done and assembled.. the results were not satisfying for me. I did gain more travel. The modified durango box now has approx 3.25 input shaft turns. Output shaft now turns slightly more ! but still less than my stock XJ box ! I compared the boxes next to eachother and made marks and visually compared how much the output shaft turns on each box. Its a few degrees less.. maybe 5-10 degrees. So I think I'm gonna put my stock box back in. There is nothing to be gained with this durango box for me.
So after all is done and assembled.. the results were not satisfying for me. I did gain more travel. The modified durango box now has approx 3.25 input shaft turns. Output shaft now turns slightly more ! but still less than my stock XJ box ! I compared the boxes next to eachother and made marks and visually compared how much the output shaft turns on each box. Its a few degrees less.. maybe 5-10 degrees. So I think I'm gonna put my stock box back in. There is nothing to be gained with this durango box for me.