Marv 845 #1 Posted March 22, 2015 I have a transmission that the shift lever retainer screw broke when attempting to unscrew it. Unfortunately it broke recessed in the boss. No way to get a purchase on it. Of course the screw is hardened and drilling doesn't seem likely. What is the "magic" way to extract it? Marvin Share this post Link to post Share on other sites
redhead 10 #2 Posted March 22, 2015 I have a transmission that the shift lever retainer screw broke when attempting to unscrew it. Unfortunately it broke recessed in the boss. No way to get a purchase on it. Of course the screw is hardened and drilling doesn't seem likely. What is the "magic" way to extract it? Marvin try a carbide bit to drill with Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,503 #3 Posted March 23, 2015 That broken part of the screw should not be tight in the casting. A good left hand drill bit may bring it out. Shops that rewind electric motors use a braided and varnished wire cover/loom to protect the winding wires where they come out of the assembly. I have used a short piece of that a bit longer than a length of 3/16" steel brake tubing glued to the inside of the tube to hold it about 1/8" from the end of the tube. Take a mig welder and feed the wire inside the loom until it hits the set screw. Now weld the set screw to the steel tubing. Shouldn't take much and turn the screw out with your fingers after it cools. The cooling is important because it seems to shrink the screw to make it even looser than it is now. Garry 1 Share this post Link to post Share on other sites
Marv 845 #4 Posted March 28, 2015 Thanks redhead. I doubted that would cut the hardened screw. Garry, interesting suggestion. So the braided varnished loom insulates the mig wire from the tube so it welds only at the end of the tube in contact with the screw. I will have to look for something else that will do the same thing. Maybe some kind of ceramic tube. Marvin Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,503 #5 Posted March 28, 2015 I don't know how much heat that loom will take but it lasted long enough to get the job done. Was curious to know why the bolt I removed broke because it only held a cover plate on. It was in a blind hole so could not turn it on through. It was so hard you could not scratch it with a file. Garry Share this post Link to post Share on other sites