Done beating a dead horse looking for reasons and solutions why the front driveshaft splines failed but this modification to groomer coupler probably won't hurt especially reducing hard impacts when starting and stopping. Made this pin coupler with junk I had lying around 15 yrs ago for a trailer to pull behind a snowmobile yes it's crude, but works better than I imagined. Haven't snapped an non reinforced bumper on a snowmobile since. Eliminated hard impacts when starting and stopping. I've seen similar with folks using hockey pucks unsure of results (I use those for hockey only lol) anyways used a medium duty spring I cut in half welded a washer to shaft midway and stoppers on both ends. I suppose if I had a groomer, I'd use a heavier spring, thicker metal, and weld it all up with 7018 from the get go.