Well as luck would have it I broke a rear stud on the hub, and lost that taper washer for my aluminum wheels. Also had 3 others loose... I had been hearing a popping noise in that rear corner for some time, that would come and then go, then come back again. It seemed to be getting worse. But on quick e+amination I had found nothing loose or out of place.
After a 10 mile run that turned out to be the last one of the season .. I saw the broken stud... I did see however that this year I put over 100 hrs. on the ST4..
There is one hole in the wheel that has suffered some wallowing out, it is the one the stud broke on. For that one I made a "acorn" washer from some 1144 stress proof shaft. It larger outside diameter is right at 1" and the taper is 60 deg.. I set my compound rest for 60 and used it to cut the taper on the outside. I bored the center hole to 7/16".. Ne+t, I then put on a small boring bar in the tool post and again using the compound only bored the 60 deg. angle into the center hole. By measuring the thickness of an original acorn washer, I knew when to quit. Parted it off, easily as I cut the outside taper with the small end towards the headstock, large end toward the tailstock... And of course the inside taper the same way, forming a "bowl" of straight sides..
I will be checking the fit of the acorn washers to the wheel on the bench very carefully, and maybe messaging the hole in the wheel a bit to clean up minor damage. I will do this test fit to each hole in the wheel, along with the washer that will be used for that stud. I need to make sure that it is really clamping the wheel to the hub, not getting hung up at the bottom of the tapered hole in the wheel and pinching it on deformed wheel stud holes.. Might use some machinist's blue to help me get good contact with the wheel. I had better check each one carefully for fit. And retorque it frequently for a while after each run to take up any wearing in of these acorn washers.
Just wanted to let you guys know this isn't a hard part to make. The second and third one's go much faster than the first.
Regards, Kirk