Combines help on a couple part n s

canuck, That may be like finding a needle in a haystack. You are looking for parts on a Denison Mark IX hydro that was used in N6 ser. n 3501-7700 and N7 ser. n1701-4800. Most of the time the ones that you find in the salvage yards are just as bad as what you have. We have converted two combines back the the Dyna-Power hydro unit for $500-$750 used from salvage yard. You just need to get complete hydro including bell housing,drive end plate and drive sheave. you will also have to make a couple of hydraulic hoses if you don't get them also. Not a bad job to convert back to older style hydro but a lot less expensive in the long run and parts are more readily available. Hyper Harvest II

I have them in new and used. The used are in a hydro but I'd sell whole hydro for half the price of them parts. Other posibility if you had the time is find a coupling that matches spline in drive cap (feed reverser sprocket does) and then go to machine shop to have chucked up in lathe. Have them remove old spline and them weld new coupling in place on center. There are shops that can renew splines on shaft as well. Newer Denison hydro and Sundstrand hydros will also fit in place of your older Denison with floating pulley but you would have to match up the proper pulley and mount plate. This would take some time but if you could get one of these hydros at a decent price it might be worth it. Good luck