clintonnut 126 #1 Posted March 1, 2011 Hey guys, Trying to get the RJ-58 going as it was the victim of a schnacke starter nut shear off. Broke the flywheel nut threads off flush with the taper. I am going to pull the crank out and cut 3/8-24 threads in the end using a lathe and put a stud in it. The threads for the flywheel nut are 7/16-20. I tried to make a stud (4 times) out of a grade 8 bolt by cutting it down on one half to the spec to cut 3/8-24 threads but every time I try it, the threads come out crooked and give the stud a wobble effect when I test its straightness in the lathe. I cant find a 1.5-2" stud that has half of each type of thread anywhere. I can't tap the crank to 7/16-20 because it will make the walls of the tapered end too thin. Any help? Charlie Share this post Link to post Share on other sites
VinsRJ 721 #2 Posted March 2, 2011 Charlie, when you are cutting down the threads for the 3/8ths are you using the leathe? How about going big........... using the lathe... turn a 1/2 inch Grade-8 bolt down to the diameter required for 7/16-20 threads and then turn the other end down for 3/8-24 threads. That way you know the center line will the dead on. Where's Coadster32 when you need him :thumbs: Share this post Link to post Share on other sites
clintonnut 126 #3 Posted March 5, 2011 I do the threads with a die by hand. If I cut down a 1/2" bolt to 7/16 would it take enough off to get rid of the 1/2" threads? Still need to figure this out. Poor RJ hasn't ran since May! Charlie Share this post Link to post Share on other sites
VinsRJ 721 #4 Posted March 5, 2011 To be honest with you I have never measured a 1/2 bolt up.... but now that you said that you may need to go larger. You should be able to get it straight threading by hand, so long as, your center line from one thickness to the other is dead nuts straight. I take it you are trying to save a Kohler? Cause if it was a Clinton you'd have what you needed "In Stock!" :thumbs: Share this post Link to post Share on other sites
clintonnut 126 #5 Posted March 5, 2011 It is a clinton 1200 that Has a 7 year old crank in it Share this post Link to post Share on other sites
sorekiwi 761 #6 Posted March 5, 2011 To be honest with you I have never measured a 1/2 bolt up.... but now that you said that you may need to go larger. The minor diameter of a 1/2" UNF thread is right at 7/16". UNC its about .404". Unless you use a die holder mounted in the tailstock, its still pretty hard to get a die to start dead straight. Can you single point the threads on there? Share this post Link to post Share on other sites
