I'm so thankful for this site. I had a terrible time finding the right seals for my steering cylinders until I found this thread. Thank you so much for sharing those part numbers.
I figured out how to get the retaining clip in place again after replacing the seals and wanted to share how I did it.
The rod has a bevel on the very end that the retaining clip will sit on to hold it in position to push against a lip at the bottom of the cylinder.
When the rod is pushed all the way into the cylinder, that lip will force the retaining ring past the high spot on the rod and into the groove.
The problem is, you can't set the clip on the bevel before you slide the rod into the cylinder. However, you can put the clip into the cylinder and, holding the cylinder vertically with the opening on the bottom, get the clip to lie flat on the lip above the seals. Still holding the cylinder vertically, insert the rod until you see the end through the threaded hole in the side of the cylinder. Through this hole, manipulate the clip so it rests on the beveled end of the rod.
Once the clip is in position, push the rod all the way into the cylinder until it stops. Finally, still holding the cylinder vertically, drop it from a height of 8 or 10 inches into a hard surface, like a concrete floor.
That will pop the clip into the groove, preventing the rod from coming all the way back out of the cylinder.
I'll attach some pictures I took during my re-assembly.