ri702bill 8,482 #1 Posted April 17, 2021 (edited) All: Last fall as I was switching the summer turf tires for the loaded ones with chains for plowing, I checked the tightness of the single setscrew over the Woodruff key on the C81. I backed off the jam nut and to my surprise, about 2/3 of the screw came out with it (probably a parting gift from the previous owner). The remaining portion is tight - I am in the process of drilling the top half thru with a 3/16" carbide drill so I can reinstall it and use it as a guide to drill the lower portion. I plan to try an Easy-out after I soak the screw with PB Blaster. 1. I do not want to damage the hub. 2. I have ordered new 1" long square set screws. 3. If I damage the Woodruff key, I'll replace it. Has anyone run into this and had good success in removing the remaining portion so the hub can be removed?? Bill Edited April 17, 2021 by ri702bill Share this post Link to post Share on other sites
pfrederi 17,865 #2 Posted April 17, 2021 No experience but I will watch your progress with great interest. i broke an alloy steel set screw off flush on one of my chargers.... Share this post Link to post Share on other sites
8ntruck 7,080 #3 Posted April 17, 2021 (edited) A left handed drill bit might help. If it catches the stub of the set screw just right, it will help loosen it, or maybe back it out. Good luck. Edited April 17, 2021 by 8ntruck Share this post Link to post Share on other sites
ri702bill 8,482 #4 Posted April 20, 2021 So far - partial success. I was able to drill a hole thru the broken off portion using a carbide center drill and 3/16" carbide drill bit in the lathe. I then used it as a guide to use the 3/16" bit to drill a full diameter into the part in the hub. I have a couple of TiN coated left handed cobalt drill bits on order that should arrive today - more to follow ..... Bill 3 Share this post Link to post Share on other sites
ri702bill 8,482 #5 Posted April 21, 2021 Success!!!! It took a bit of doing and a second set of eyes (and tools) but I was able to drill thru the screw and into the key. My son suggested I try what he does with broken lock bolts. I supported the hub by the small diameter with wooden 4x4's and he hammered a Torx T27 bit into the screw. Next he used his cordless impact drill / driver and it backed right out. Lessons learned: I was able to drill easily with the 3/16" Tin coated left handed cobalt bit - I could not then open it up to 1/4" with the next bit, it just ruined the edge of the flutes. These bits need a full bite to work. In hindsight, the left handed bit worked, but I do not feel it freed it up at all. I tried a couple of "Easy-outs" with no success - the screw is harder than the tool and could not get them to bite. Next up - remove the hub and replace the Woodruff key. Bill 3 4 Share this post Link to post Share on other sites
frankdalio 0 #6 Posted June 22, 2022 I had a damaged hub and went to my auto parts store and got a 3/8" heli-coil kit. You MUST use the exact drill bit size recomended. It's now as strong or stronger then the original Share this post Link to post Share on other sites
moe1965 744 #7 Posted June 22, 2022 Excellent those set screws are hardened I'll put that a n my memory bank 1 Share this post Link to post Share on other sites
