Apparently I lost the starting threads to a bolt hole on my motor, it’s holding up my whole project. Most if the threads are fine, it’s just I can’t get the bolt started (tried for almost an hour in different ways. Do I need to tap the entire whole for a new bolt or can I save the existing threads?? I don’t own a Tap and die set, and have never used one.
It’s in a bad place of course so I’m not sure what the best way to proceed would be.
Thanks for any advice you can give me !!
You want to use a thread chaser.
Sears sells these.
http://www.sears.com/craftsman-48-pc-sae-metric-thread-restorer-kit/p-00942275000P
Instead of using a tap which can cut new threads, a chaser restores the original threads.
Saved my ass a few times.
Tester
O’Rielly’s will rent you a thread restorer die, also known as a roll forming die. If you do it in their parking lot, they will often let you just take it to the parking lot, but if you need to take it home, you pay a deposit. When you return the set, you get your deposit back so in the end, it costs you nothing.
Another option which might be the better choice for you is to take (or tow) the car to you local and automobile machine shop. Ask your mechanic for a recommendation for a good machine shop in the area. They could fix you up straight away and the fee would be pretty reasonable I expect. They do this all the time and have all the tools for this kind of job. Might save yourself from issuing some curse words in the process … lol …
If you really bung up the thread chasing it, you can drill it out and install a Heli-coil (or generic thread insert) to fix it. So don’t get too nervous that this is your last option. If there is enough metal around the hole, you may also be able to drill and tap the next larger size bolt OR the next larger English size (assuming metric bolts). The chaser should get the job done but you have options if it does not.
If the thread chaser leaves threads that just are not strong enough I have had success with using a bolt with longer threaded area, putting a little J B Weld with a toothpick into the threads in the hole, putting some on the bottom threads of the bolt, installing it in the hole and the next day cutting off the bolt at the appropriate place to make a stud, hanging the part and using a nut.
Borrowed a thread repair kid form autozone and it worked like a champ!! Then I proceeded to snap off a stud, but that’s another story (I sware this thing is fighting me every step of the way )…
Thanks guys !!
This is a really cool tool for internal thread restoration.
Try a new bolt. U probably have slightly worn down the initial threads on bolt. I don’t follow the comment that the initial threads are bad but than the rest of threads are ok. Why can’t u put extra pressure on bolt and push it into the threaded hole? Any bolt, for the most part gently threads into the female thread. It is only at the last 1/4 turn where you achieve max torque. Put on a lugnut. Loose at first, than it get “tight” when lugnut actually squeezes against wheel. Same with any bolt.
If you cross thread it when forcing the bolt in, it will make the problem worse. He will either mess up the good threads or snap the bolt off trying to force it. Then he may never get it out. Patience and the right tool always win.