Steering Shaft for 1983 John Deere 1050

[Snowstorm]

I am trying to find a steering shaft for a 1983 John Deere 1050. The shaft has to be replaced as the bearing surface on the threads on the bottom end of the shaft are separating. The shards of metal jam the ball bearings and force the tubes apart, spilling the bearings into the steering box. I've rebuilt it seval times over the last few months but it doesn't last long. The JD Part number is CH13316, but according to many parts managers and websites, that number has been discontinued. I've called used tractor places all over the country without any luck. Would appreciate any suggestions on how to locate a new shaft or a fair condition used shaft. Thanks. Kevin

You can see it at this link - it comes as a unit - the shaft with ballnut attached:
OEM Parts

 

[KubotaSam]

Your JD 1050 was built by Yanmar. Hoye tractor should be able to help. Check out this thread.http://www.tractorbynet.com/forums/yanmar/155898-yanmar-jd-1050-a.html