John Deere Model 68 advice needed.

[I posted this in the wrong sub-forum a week agowith no response.]

Yes, I have an old John Deere Model 68 riding mower that just won't die. It's a real shame nobody makes mowers this size (34") anymore, because it's ideal for getting the grass on a half-acre lot cut in an hour. Not much out there between push and self-propelled mowers and 42" tractors that are too big to mow in and out of ditches or fit the average garden shed.

Anyway, I was cutting the grass yesterday when I lost drive. The belt was still there, but the right rear wheel flopped around, so I figured I'd broke the axle, which isn't available anymore. Fortunately, my neighbour loaned me his Honda H3011H to finish the job. He's replacing it with a small zero-turn mower and I offered to buy it.

Anyway, today I tore into the JD 68 to see what actually happened and saw that the weld where tubular axle joins the wheel mounting flange had broken. I hope there's someone around here familiar with this model that can offer advice.






(The first picture doesn't show the break very well, but shows what the end of the axle looks like, which doesn't resemble what is in the parts book, below.



Now I welded up the cracked weld (I won't show you what my "handiwork" looks like), but I'm trying to figure out why my axle differs from what's in the parts book. The inner shaft (#11) comes right through the mounting flange on mine and has a big washer welded on the end (which you can see in the first picture), while the book shows a collar and cotter pin (#9 & #10) on the end of the shaft. Would mine be a cobbled-up repair job, or how the factory made them? I also notice that where the inner shaft turns inside the outer shaft when the differential is working there is no lubrication, so I squirted oil in the 2 holes before mounting the wheel. Should there be enough oil or grease in the diff or chaincase so it runs out along the shaft? I also read elsewhere that Item #12 is a roll pin (it says groove pin) that gets deformed and difficult to remove when disassembling the axle. It looks like I have a bent nail in there that rattles around loose. Should I replace it with a nut and bolt?