What to do? Need your help.

[laryh]

Due to my own stupidity I broke a pressure plate bolt and hardened ez-out in my 59 flywheel. My question is can I get by with a heli-coil or must I have the hole welded and retapped to original?

[Brendan]

can you use a reversible drill bit?

[J Franklin]

Use a Helicoil or similar repair unless you want to go to all that other trouble for perceived peace of mind.

[Andy]

I don't think you are going to weld an iron flywheel. i believe the hole in the flywheel is drilled thru. You can get at the backside and either drill if it is not clear and then tap the easy out from behind. I would get the remains of the bolt cherry red and then try a torx bit as and easy out.

[Bruce Lancaster]

Yes...drill into it from behind to remove as much as possible. This will likely destroy the drill bit used when it gets to the easy out, but that's cheap at this point. If necessary chew away a little more around the tip of the out with a Dremel and little ball grinder, punch the thing out. With careful eye for center you could drill out center of remaining bolt til it is just a shell, then pick out the threads...but I bet you have a crooked and off-center hole from drilling for the outener, which will make accurate drilling very difficult. If this is the case, enlarge existing hole til you begin to see the back of the threads at whatever point is closest. Start poking and prodding...at this point the remainder should be getting loose. With care you should be able to pick out the hollowed bolt and save the threads in the wheel.

[Pete]

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If you don't feel comfortable doing it with Bruce's method,take it to a shop and have it EDM'd out..If they can't save the old threads a Helicoil or Threadsert will work fine.

[Pothole Jim]

Is the easy-out still in the hole? I take a chisel and hit the easy-out, many times the easy-out will break, since it broke once, it will break easier. If the hole was drilled all the way through place a drift punch on the backside and drive out the broken easy-out. Once out, deal with damages threads.

It would be cheaper to clock the pressure plate and redrill all new holes than the cost of the EDM process.

Have another flywheel? sounds a whole lot cheaper and easier, to me.

[laryh]

I should have given more information the first time. The broken stuff is all out but the threads are showing some damage. The engine is a new rebuild on a stand. The flywheel has been surfaced and balanced. I am trying to repair with minimum labor and expense. Another thought is can the hole be drilled and tapped one size larger without throwing the balance way out? Also I didn't know the flywheel was iron, I just assumed it was steel. Keep your ideas coming I appreciate them. Anyway here is a couple of pictures of the engine.

[01aford]

Flywheels are cheap and easy to find. I would get it replaced.

[Andy]

I would sure heli-coil it. You will never notice any unbalance. I would check the integrity of the threads you have first. Bolt it up and put a torque wrench on it and over torque it slightly. If it holds you are fine. Internal threads are stronger than external threads.

[FRANK PKNY]

If the easy out is still in there drill a small hole from the back and punch it out . try to keep perfect center with the drill . Then from the back use a slightly larger drill and try to drill out the broken stud. Sometimes the drill will force out the broken bolt if not go slightly larger till you get to the threads. If the threads are ruined just use an Helicoil per their instructions. JMHO Frank pkny

[Ronnie]

That's what heli coils are made for.
It's an easy fix I have done 100's of heli coils.
You will be up and running in no time.

Regards

Ronnie